Answer:
6.25gm
half life is 66hrs 11 days is 24*11 then take that and divide by 66 to find out how many time it will have halved and half 50 by that many times
Explanation:
If you have 50 grams of Molybdenum-99, after 11 days, 2.7 g will remain.
Molybdenum-99 follows first-order decay.
What is first-order decay?First-order decay means that for a population of atoms (e.g. radioactive), molecules, or anything else, a constant fraction/unit time is converted to something else.
The half-life (th) of Mo-99 is 66 h.
We will find its rate constant (k) using the following expression.
k = ln2 / th = ln2 / 66 h = 0.011 h⁻¹
Next, we will convert 11 days to hours, knowing that 1 day = 24 h.
11 d × 24 h/1 d = 264 h
If we start with 50 g of Mo-99, we can calculate the remaining mass after 264 h using the following expression.
[tex][Mo] = [Mo]_0 \times e ^{-k \times t} }\\\\[Mo] = 50g \times e ^{-0.011 h^{-1} \times 264 h} } = 2.7 g[/tex]
where,
[Mo] is the final amount of Mo-99.[Mo]₀ is the initial amount of Mo-99.t is the elapsed time.If you have 50 grams of Molybdenum-99, after 11 days, 2.7 g will remain.
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Hello, this is a science task and it is due today I would really appreciate it if you guys can help me answer and explain what is the difference between expansion and contraction:) I will mark brainliest!
Answer:
Expansion: increase in size Contraction: decrease in size
Explanation:
The increase in size of an object on heating is called expansion where as the decrease in size of an object on cooling is called contraction.
help asap pls,
find the percent composition
Explanation:
1. Pb(CO3)2
Element Number Mass Percet Composition
Oxygen 6 16.00 29.34%
Carbon 2 12.01 7.34%
Lead 1 207.21 63.32%
2. Ga(OH)3
Element Number Mass Percet Composition
Hydrogen 3 1.0079 2.50%
Oxygen. 3 16.00 39.75%
Gallium 1 69.72 57.74%
3. P4O10
Element Number Mass Percet Composition
Oxygen. 10 16.00. 56.36%
Phosphorus. 4 30.97 43.64%
4. Ca3P2
Element Number Mass Percet Composition
Phosphorus 2 30.97 34.00%
Calcium. 3 40.08 66.00%
5. Ti(NO3)3
Element Number Mass Percet Composition
Oxygen. 9 16.00 61.56%
Titanium. 1 47.87 20.47%
Nitrogen. 3 14.01 17.97%
(GIVING BRAINLIEST!!)
Identify and describe the different forms of precipitation shown in the images.
Answer:
snow, hail, rain
Explanation:
precipitation is the transfer of water in any form from the atmosphere to the land or sea surface
Forms of Precipitation. It can be liquid or solid; the main precipitation types are rain, sleet, snow, ice pellets, hail, and drizzle.
Why are there different forms of precipitation?There are different forms of precipitation based on atmospheric conditions. Warmer atmospheric conditions might result in rain, drizzle, or hail (if it's a thunderstorm). Colder atmospheric conditions might result in snow, sleet, freezing rain, or ice crystals.
What are the 4 main types of precipitation?The four main types of precipitation are rain, snow, sleet, and hail. Rain is liquid precipitation that falls during many parts of the year. Hail is associated with thunderstorms and generally falls in warmer temperatures. Snow and sleet are frozen and generally fall in colder temperatures.
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(b) Why must acidic gases be treated before they are released into the atmosphere?
Answer:
because they react with other gases of atmosphere and pollute the environment
Which represents the overall (net) reaction of this mechanism: step 1: H2O2 + I- → H2O + OI- step 2: H2O2 + OI- → H2O + O2 + I- Note that I- acts as a catalyst in this reaction.
A. 2H2O2 → 2H2O + O2
B. H2O2 → H2 + O2
C. H2O2 + I- → OI- + H2O
D. H2O2 + OI- → H2O + O2 + I-
Answer:
A. 2H₂O₂ → 2H₂O + O₂
Explanation:
1. H₂O₂ + I⁻ → H₂O + OI⁻2. H₂O₂ + OI⁻ → H₂O + O₂ + I⁻If we make a net sum of both reactions, we're left with:
H₂O₂ + I⁻ + H₂O₂ + OI⁻ → H₂O + OI⁻ + H₂O + O₂ + I⁻Grouping species:
2H₂O₂ + OI⁻ + I⁻ → 2H₂O + OI⁻ + O₂ + I⁻There is OI⁻ at both sides, so it is eliminated -same goes for the catalyst, I⁻-.
2H₂O₂ → 2H₂O + O₂Thus the answer is option A.
A 50.0 g sample of liquid water at 56.0°C, heats to 91.0 "C. How much energy is
involved in this change? (Heat capacity of liquid water is 4.17 J/gºC) (Q
=mcAT)
A. 7298 J B. 12038 J
C. 204480 J D. 17807 J
Answer:
A
Explanation:
using
mC∆t
50×4.17×(91-56)
=50×4.17×35
=7297.5
~ 7298 J
The following are all examples of good titration reactions with the exception of _____________. (7-2) Group of answer choices Ammonia (NH3) titrated with HCl titrant. Formic acid titrated with ammonia (NH3) as a titrant. I- titrated with Ag titrant, forming a complex with a tiny Ksp. Potassium Hydrogen Phthalate (KHP) titrated with NaOH titrant. NaOH titrated with HBr titrant.
Answer:
Formic acid titrated with ammonia (NH3) as a titrant
Explanation:
We have to look at something very critical here and that is, considering whether the acid/ base is strong or weak.
For a weak acid weak base titration, there is no suitable indicator neither is there any sharp pH range because no sharp change occurs. So, for a weak acid-weak base titration, there is only a very small change in pH at the equivalence point. This makes it impractical to carry out a weak acid- weak base titration.
Formic acid is a weak acid and ammonia is a weak base. Hence, Formic acid titrated with ammonia (NH3) as a titrant is a bad titration
How many grams of sodium hydroxide are needed to completely react with 50.0 grams of H2SO4?
Answer:
48.0 grams
Explanation:
The products of this reaction are nitrogen gas and water. How many grams of sodium hydroxide (NaOH) are needed to completely react with 50.0 grams of sulfuric acid (H2SO4) to form sodium sulfate (Na2SO4) and water? 2NaOH + H2SO4 → Na2SO4 + 2H2O ; 48.0 grams of NaOH are needed.
51.020 grams of sodium hydroxide is needed to completely react with 50 grams of sulfuric acid according to stoichiometry.
What is stoichiometry?It is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.
Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.
The reaction between sodium hydroxide and sulfuric acid is as follows,
2 NaOH + H₂SO₄[tex]\rightarrow[/tex]Na₂SO₄+2 H₂O
From the reaction, it is clear that 2 oles of sodium hydroxide react with 1 mole of sulfuric acid to give products. According to molar mass concept,
100 g of sodium hydroxide gives 98 g of sulfuric acid
Therefore, 50 gram of sulfuric acid requires 50×100/98=51.020 g
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5 Describe how seawater forms layers
Answer:The ocean forms layers because the water has different density throughout. 2. Water with higher density sinks to the bottom while water with lower density sits on the top. ... Low-density water tends to be warmer and less saline, while high-density water is generally cooler and more saline.
Explanation:
1. Mixing Water at Two Temperatures
a. One flask contains 150.0 g water at 20.0 °C. A second flask contains 350.0 g water at 95.0 °C. If the two water samples are mixed, what will the final temperature of the water be?
-Assume that the density of water it 1.000 g/cm^3
-The specific heat capacity for water is 4.184 J/g °C
Answer:
[tex]T_f=72.5\°C[/tex]
Explanation:
Hello!
In this case, since this a problem in which the cold water is heated by the hot water, we can write:
[tex]Q_{hot}+Q_{cold}=0[/tex]
Thus, by plugging in the mass, specific heat and temperatures, we obtain:
[tex]m_{hot}C_{hot}(T_f-T_{hot})+m_{cold}C_{cold}(T_f-T_{cold})=0[/tex]
Now, we can also write:
[tex]m_{hot}(T_f-T_{hot})+m_{cold}(T_f-T_{cold})=0[/tex]
Then, after applying some algebra, it is possible to obtain:
[tex]T_f=\frac{m_{hot}T_{hot}+m_{cold}T_{cold}}{m_{hot}+m_{cold}}[/tex]
If we plug in, we obtain:
[tex]T_f=\frac{350.0g*95.0\°C+150.0g*20.0\°C}{350.0g+150.0g}[/tex]
[tex]T_f=72.5\°C[/tex]
Best regards!
For the balanced equation shown below, what would be the limiting reagent if 42.3 grams
of N2O5 were reacted with 9.18 grams of H2O?
N2O5+H2O---> 2HNO3
A. HNO3
B. H20
C. N205
Answer: A. HNO3
Explanation:
compound composed of cations and anions the forces of attraction that bind oppositely charged ions together lowest whole-number ratio of ions in an ionic compound a depiction of the valence electrons as dots around the symbol for an element a mixture of two or more elements, at least one of which is a metal the attraction of the free-floating valence electrons for the positively charged metal ions ions of the halogen atoms the electron(s) in the highest occupied energy level of an atom the number of ions of opposite charge that surround each ion in a crystal Atoms in a compound tend to have the electron configuration of a noble gas. Shows the kinds and numbers of atoms in the smallest representative unit of a substance a. halide ions b. alloy c. octet rule d. formula unit e. electron dot structure f. ionic compound g. ionic bonds h. coordination number i. chemical formula j. valence electrons k. metallic bond
Answer:
compound composed of cations and anions the forces of attraction that bind oppositely charged ions together - ionic compound
lowest whole-number ratio of ions in an ionic compound - formula unit
a depiction of the valence electrons as dots around the symbol for an element - electron dot structure
a mixture of two or more elements, at least one of which is a metal - alloy
the attraction of the free-floating valence electrons for the positively charged metal - metallic bond
ions of the halogen atoms - halide ions
the electron(s) in the highest occupied energy level of an atom - valence electrons
the number of ions of opposite charge that surround each ion in a crystal - coordination number
Atoms in a compound tend to have the electron configuration of a noble gas - octet rule
Shows the kinds and numbers of atoms in the smallest representative unit - chemical formula
Explanation:
An ionic compound is composed of oppositely charged ions held together in a crystal lattice. The lowest whole-number ratio of ions in an ionic compound is known as the formula unit. The number of ions of opposite charge that surround each ion in a crystal is called the coordination number. Ions of the halogen atoms are negatively charged and are called halide ions
Elements are composed of atoms, the electron(s) in the highest occupied energy level of an atom are called valence electrons. In metals, the attraction of the free-floating valence electrons for the positively charged metal is called the metallic bond. For atoms of elements, a depiction of the valence electrons as dots around the symbol for an element is called the electron dot structure or Lewis structure.
A combination of elements may be a compound or an alloy. An alloy usually contains at least one metal. For compounds, the chemical formula Shows the kinds and numbers of atoms in the smallest representative unit. Atoms form compounds because atoms in a compound tend to have the electron configuration of a noble gas this is the octet rule.
The correct match of the given statement are 1 - f. ionic compound, 2- d. formula unit, 3 - e. electron dot structure, 4- b. alloy, 5- k. metallic bond, 6- a. halide ions, 7- j. valence electrons, 8- h. coordination number, 9 - c. octet rule, 10- i. chemical formula.
Ionic compounds are made up of oppositely charged ions that are kept together in a crystal lattice. The formula unit is the lowest whole-number ratio of ions in an ionic compound.
The coordination number is the number of ions with opposite charges that surround each ion in a crystal. Halide ions are halogen atom ions that are negatively charged.
Elements are made up of atoms, and the electron(s) in the atom's highest occupied energy level are known as valence electrons. The metallic bond refers to the attraction of free-floating valence electrons to positively charged metals in metals.
The electron dot structure or Lewis structure is a representation of the valence electrons as dots around the symbol for an element for atoms.
A compound or an alloy is a mixture of components. A metal is frequently present in an alloy.
The chemical formula is used for compounds. The types and numbers of atoms in the smallest representative unit are displayed.
The octet rule states that atoms in a compound tend to have the electron configuration of a noble gas.
Therefore, the correct matches are: 1 - f. ionic compound, 2- d. formula unit, 3 - e. electron dot structure, 4- b. alloy, 5- k. metallic bond, 6- a. halide ions, 7- j. valence electrons, 8- h. coordination number, 9 - c. octet rule, 10- i. chemical formula.
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The given question is incomplete, so the most probable complete question is,
Match the correct statement with their appropriate terms:
Compound composed of cations and anions, the forces of attraction that bind oppositely charged ions together.Lowest whole-number ratio of ions in an ionic compound.A depiction of the valence electrons as dots around the symbol for an element.A mixture of two or more elements, at least one of which is a metal.The attraction of the free-floating valence electrons for the positively charged metal.Ions of the halogen atoms.The electron(s) in the highest occupied energy level of an atom.The number of ions of opposite charge that surround each ion in a crystal.Atoms in a compound tend to have the electron configuration of a noble gas.Shows the kinds and numbers of atoms in the smallest representative unit.How many particles are in 4g of NaCl? (1mol of NaCl = 58g) – 2 step conversion
Answer:
4.16 * 10²⁴ particles
Explanation:
1. We convert from grams to moles
4 g NaCl / 58 g of NaCl = 0.0689655172 moles
-> 0.0690 moles
2. Now we will convert from moles to particles by multiplying by avogadro's number..
0.0690 * 6.022 *10²³ = 4.15518 * 10²⁴ particles or 4.16 * 10²⁴ particles
Hail is falling down from the sky at 50 miles per hour. Is this an example of speed,
velocity or acceleration?
Explanation:
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read carefully and do this questions all part all questions if someone do this questions I will make you brainly and give you thanks.
Answer:
Question 1.
a. the product of the reaction above that contains calcium is calcium chloride, CaCl₂.
b. the reactant, hydrochloric acid, HCl contains hydrogen
c. the product water, H₂O contains hydrogen
d. the reactant, calcium carbonate, CaCO₃ contains carbon
e. The product carbon (iv) oxide contains carbon
Question 2:
a. atoms of hydrogen and oxygen bonded together as a single compound known as water molecules are present at the start of the reaction
b. two molecules of water are present at the start of the reaction
c. two individual atoms of hydrogen and oxygen existing as molecules are present at the end of the reaction.
d. at the end of the reaction, two molecules of hydrogen and one molecule of oxygen are present.
Question 3:
a. total mass of products = 187 g
b. if Chinua starts with 10 g of magnesium, the same 10 g of magnesium will be found in the magnesium sulfate
Explanation:
Question 1: The equation of the reaction between calcium carbonate and hydrochloric acid is given as follows: + 2HCl ---> CaCl₂ + H₂O + CO₂
a. the product of the reaction above that contains calcium is calcium chloride, CaCl₂.
b. the reactant, hydrochloric acid, HCl contains hydrogen
c. the product water, H₂O contains hydrogen
d. the reactant, calcium carbonate, CaCO₃ contains carbon
e. The product carbon (iv) oxide contains carbon
Question 2: the equation of the reaction in which water is broken down to hydrogen and oxygen is as follows: 2H₂O ----> 2H₂ + O₂
a. atoms of hydrogen and oxygen bonded together as a single compound known as water molecules are present at the start of the reaction
b. two molecules of water are present at the start of the reaction
c. two individual atoms of hydrogen and oxygen existing as molecules are present at the end of the reaction.
d. at the end of the reaction, two molecules of hydrogen and one molecule of oxygen are present.
Question 3: The equation of the reaction between magnesium and sulfuric acid is given as follows: Mg + H₂SO₄ ---> MgSO₄ + H₂
molar mass of Mg = 24.0 g; molar mass of H₂SO₄ = 98.0 g
a. when 37.0 g of magnesium is reacted with 150 g of H₂SO₄, the total mass of products of the reaction is equal to the total mass of the reactants according to the law of conservation of mass.
Total mass of products = 150 + 37 = 187 g
b. if Chinua starts with 10 g of magnesium, the same 10 g of magnesium will be found in the magnesium sulfate
how to get a girlfrend at age 70
How much volume would a sample of galena have it its mass was 300 grams?
Answer:
8272uegdgd9w0wpwlw0w-w[w9w8177w7w7
Which of the following particles has the smallest
mass?
A) electron
C) neutron
B) hydrogen atom
D) proton
Answer:
AN ELECTRON HAS THE SMALLEST MASS!
Answer:
A) electron
good luck, i hope this helps :)
Draw the organic product(s) formed when CH3CH2CH2OH is treated with each reagent. a. H2SO4 e. SOCl2, pyridine i. [1] TsCl, pyridine; [2] NaSH b. NaH f. PBr3 j. POCl3, pyridine c. HCl ZnCl2 g. TsCl, pyridine d. HBr h. [1] NaH; [2] CH3CH2Br
Answer:
See answer below
Explanation:
In this case, we are treating an alcohol with different reagents to give different products. In the picture below you have the draw of each product, and here, the explanation.
a) H₂SO₄: In this case, it will promote an E1 reaction forming an alkene as product.
b) NaH: In this case, it will promote an acid base reaction, and the final product will be an alcoxide.
c) HCl/ZnCl₂: In this case, primary alcohols reacts with this reactive to form an alkyl halide.
d) HBr: Another reaction forming an alkyl halide with bromine in this case.
e) SOCl₂: Similar to c), it will form an alkyl chloride.
f) PBr₃: Similar to d, forming an alkyl bromide.
g) TsCl: Here it will be a sustitution reaction, where tosilate replaces the OH
h) NaH/CH₃CH₂Br: In this case it will form an alcoxide and then, a larger alkyl.
i) TsCl/NaSH: First it will form a tosilate and then, the SH group. A sustitution reaction.
j) POCl₃: A sustitution reaction forming an alkyl chloride.
See picture below for drawings.
Hope this helps
Given the atomic mass of select elements, calculate the molar mass of each salt.
Element Molar mass
(g/mol)
Beryllium (Be) 9.012
Magnesium (Mg) 24.31
Cobalt (Co) 58.93
Cadmium (Cd) 112.41
Bromine (Br) 79.90
Match the numbers to the appropriate blanks in the sentences below. Make certain each sentence is complete before submitting your answer.
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1. The molar mass of MgBr2 is The molar mass of M g B r 2 is blank..
2. The molar mass of BeBr2 is The molar mass of B e B r 2 is blank..
3. The molar mass of CoBr2 is The molar mass of C o B r 2 is blank..
4. The molar mass of CdBr2 is The molar mass of C d B r 2 is blank..
reativity of alkali metals increases down the group while reativity decreases down the group in helogens
Complete question is;
Chemical reactivity of alkali metals increases down the group while reactivity of halogens decreases down the group. Give reasons
Answer:
Explained below
Explanation:
Alkali metals exhibit reactivity due to their electropositivity. Now, for alkalis, their electro-positivity increases down their group. Since their reactivity increases with increase in electropositivity, it means their reactivity also increases down the group.
Whereas, the reactivity of halogens occurs as a result of their electronegativity. Now, electronegativity for halogens decreases down the group. Since their reactivity decreases with decrease in electronegativity, it means that their reactivity will also decrease down the group.
Why is n-hexanol is not soluble in H2O
Answer:
Ethanol is soluble in water because it has a hydroxyl group which allows it to form hydrogen bonds with the water molecules. This is why hexanol is not soluble in water.
3.Which of these is NOT part of the cell theory? * "
all living things are made of cells
Ocells come only from other cells
cells are the smallest living unit of an organism
O all living things have blood cells
Answer:
Cells are the smallest living unit of an organism
Answer:
all living things living things have blood cells
Explanation:
this is because robert hooke did not make this apart of the theory
Determine the molecular formula for a compound that has a molecular mass of 52.0 g/mole
and and is composed of 92.31% carbon and 7.69% hydrogen.
Answer:
C4H4
Explanation:
92.31% of 52.0 g/mol is 48.0012 g/mol
7.69% of 52.0 g/mol is is 3.9988 g/mol
Carbon has a gram-formula mass of about 12, which goes into 48.0012 about 4 times, so there should be 4 atoms of Carbon
Hydrogen has a gram-formula mass of about 1, which goes into 3.9988 about 4 times, so there should also be 4 atoms of hydrogen
Is water made of plant cells or animal cells
•plant
•animals
•niether
Answer:
i think niether
Explanation:
Zn(s) + 2 HCl(aq) —> ZnCl2(aq)
+ H2(g)
If a scientist wanted to create 10L of hydrogen gas at RTP, what mass of HCl would they need to start with?
Answer:
First write the balanced equation for the reaction of HCl with Zn (NOTE: the previous answer did NOT do this and thus obtained an incorrect answer)
Zn + 2HCl ==> ZnCl2 + H2(g)
moles of H2 desired: PV = nRT
n = PV/RT = (1 atm)(10L)/(0.0821 Latm/Kmol)(298K)
n = 0.409 mole H2 desired
moles Zn needed:
0.409 moles H2 x 1 mole Zn/2 moles HCl = 0.204 moles Zn needed
mass Zn needed = 0.204 moles Zn x 65.4 g/mol = 13.4 g Zn needed (to 3 sig. figs.)
Explanation:people always get this wrong but i got you
#3. How does a fever aid an immune response?
Answer:
it can tell and show what pathogen is in you as well what type and mutation so then your body can fight back and remember the genetic dna so then you will be immune in some way.
Explanation:
Question;
How does a fever aid an immune response?
Answer:
One type of immune cell jumps into the fray after body temperature rises, according to experiments in mice. A fever fights infection by helping immune cells to crawl along blood-vessel walls to attack invading microbes
CH3CH2CH2CH2CH3
Balanced chemical equation for this
Answer:
C5H12 + 8O2 --> 5CO2 + 6H2O
Explanation:
Complete question
Write a balanced chemical equation to represent the combustion of CH3CH2CH2CH2CH3
Solution
The given compound is pentane
C5H12
The empirical equation representing combustion of pentane is
C5H12 + O2 --> CO2 + H2O
We will first balance the carbon atoms
C5H12 + O2 --> 5CO2 + H2O
Now we will balance the Hydrogen molecule
C5H12 + O2 --> 5CO2 + 6H2O
Now we will balance the oxygen molecule
C5H12 + 8O2 --> 5CO2 + 6H2O
Please help :) hope you have a good day
Have a wonderful day :) thanks for the points
PLEASE HELP ME!! DIMENSIONAL ANALYSIS
CHEMISTRY
DUE IN 5 MINS!!!
Answer:
12 mi/h
Explanation:
Step 1: Given data
Total distance (d): 6 kmTime elapsed (t): 19 minStep 2: Convert "d" to miles
We will use the conversion factor 1 mi = 1.60934 km.
6 km × 1 mi/1.60934 km = 3.7 mi
Step 3: Convert "t" to hours
We will use the conversion factor 1 h = 60 min.
19 min × 1 h/60 min = 0.32 h
Step 4: Calculate the average speed of the runner (s)
The speed is equal to the quotient between the total distance and the time elapsed.
s = d/t
s = 3.7 mi/0.32 h = 12 mi/h