Answer:
[tex]0.25\ \text{mg}[/tex]
Explanation:
[tex]t_{1/2}[/tex] = Half-life of technetium-99 = 6 hours
[tex]N_0[/tex] = Initial mass of sample = 20 mg
[tex]t[/tex] = Time elapsed = 24 hours
Amount of mass remaining is given by
[tex]N=N_0e^{-\dfrac{\ln 2}{t_{1/2}}t}\\\Rightarrow N=20e^{-\dfrac{\ln 2}{6}\times 24}\\\Rightarrow N=0.25\ \text{mg}[/tex]
The amount of the sample that would remain is [tex]0.25\ \text{mg}[/tex].
Do you know this Ca(NO2)2 ? It's not calcium nitrate
Answer:
The answer is, in fact, Calcium Nitrate. I even looked it up to make sure, and according to PubChem, it is Calcium Nitrate. I suggest asking your teacher what this question is trying to ask because if it says it is not Calcium Nitrate, someone got it wrong.
Explanation:
The only other name I can think of, though, is Calcium Dinitrite.
Select the correct answer.
What is the formula of the compound vanadium(V) oxide? Use the list of polyatomic ions and the periodic table to help you answer.
A.
VO2
B.
VO5
C.
V5O2
D.
V2O5
E.
V2O2
Answer:
Vanadium(V) oxide is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide,
Explanation:
then it is answer D
What is the molal concentration of a sucrose (C12H22011) solution whose freezing point is
-2.00 °C? The Kf for water is 1.86 °C/m.
Answer: The molal concentration of sucrose solution is 1.07 m
Explanation:
Depression in freezing point is given by:
[tex]\Delta T_f=i\times K_f\times m[/tex]
[tex]\Delta T_f=T_f^0-T_f=0.00-(-2.00)^0C=2.00^0C[/tex] = Depression in freezing point
i= vant hoff factor = 1 (for non electrolyte such as sucrose)
[tex]K_f[/tex] = freezing point constant = [tex]1.86^0C/m[/tex]
m= molality
Putting in the values:
[tex]2.00^0C=1\times 1.86^0C/m\times m[/tex]
[tex]m=1.07[/tex]
Thus molal concentration of sucrose solution is 1.07 m
In the wintertime, you decide to buy a helium balloon at Dollar Tree. It is fully
inflated in the store. However, when you walk outside in the cold, the balloon
deflates quite a bit. So, you go back into the store, to exchange it for a different
balloon. But once you walk back into the warm store, the balloon is fully inflated!
Why does the balloon deflate outside in the cold winter weather and inflate inside
the warm store? Which gas law, (Charles, Boyle, Guy-Lussacs law) causes this to
happen?
lyse
Answer:
The reason that the balloon shrinks is because when the temperature drops, helium becomes more dense then it already is. So what happens is that its molecules lose energy, slows down and moves closer together to conserve heat and this decreases the volume inside the balloon because the helium molecules are moving closer together, rather than outward toward the shell of the balloon which cause the balloon to swell then shrink. The gas law that causes this to happen is the Charles law.
Explanation:
Answer:
When the temperature decreases the pressure decreases with it, causing it to crumple or deflate.
Explanation:
_NaHCO(s) --> _CO2+_NaCO(s)+_H2O
balance the equation
The balanced equation :
2NaHCO₃⇒CO₂ + Na₂CO₃+H₂O
Further explanationGiven
Reaction
NaHCO(s) --> _CO2+_NaCO(s)+_H2O
Required
The balanced equation
Solution
Maybe the equation should be like this :
NaHCO₃⇒CO₂ + Na₂CO₃+H₂O
Give a coefficient
NaHCO₃⇒aCO₂ + bNa₂CO₃+cH₂O
Make an equation
Na, left=1, right=2b⇒2b=1⇒b=1/2
H, left=1, right=2c⇒2c=1⇒c=1/2
C, left=1, right=a+b⇒a+b=1⇒a+1/2=1⇒a=1/2
The equation becomes :
NaHCO₃⇒1/2CO₂ +1/2Na₂CO₃+1/2H₂O x2
2NaHCO₃⇒CO₂ + Na₂CO₃+H₂O
What is the mass of a sample containing 8.53×10 to the 24th power formula units of magnesium phosphate?
Answer:
Mass = 3732.62 g
Explanation:
Given data:
Number of formula units = 8.53×10²⁴
Mass of sample = ?
Solution:
1 mole of any substance contain 6.022×10²³ formula units.
8.53×10²⁴ formula units ×1 mol / 6.022×10²³ formula units
1.42×10¹ mol
14.2 mol
Mass of magnesium phosphate:
Mass = number of moles × molar mass
Mass = 14.2 mol × 262.86 g/mol
Mass = 3732.62 g
On which sides of the Earth do high tides occur?
K₂O(s) + H₂O (l)-> KOH(aq)
Answer:
K20(s)+H2O(L) -> 2KOH(aq)
Explain why in this crossing all of the hedgehog offspring are brown even though they all carry the white gene?
2. Which WHMIS symbol would require gloves? A ventilator? A gas mask?
Answer:
Ventilator
Explanation:
What is the WHMIS 1988 classification? ... Symbol for Class D1 ... Direct contact with the liquefied gas can chill or freeze the skin (frostbite). ... Take precautions to ensure your own safety before attempting rescue (e.g. wear ... Increase ventilation to area or move leaking container to a well-ventilated and secure area.
So B. is the Right Choice!
The _energy of the baseball is the sum of the kinetic energy and _energy of the particles that make up the baseball
Answer:
Mechanical energy
Kinetic energy
Explanation:
The mechanical energy is the sum of the kinetic and potential energy of the particles that make up the baseball.
Mechanical energy is made up of kinetic energy and potential energy. When the baseball is in motion, the particles make use of the kinetic energy, also known as motion energy and when the ball is not in motion the particles make use of the potential energy, also known as stored energy.
In negative adsorption the concentration of the solution is
Answer:
This is called negative adsorption. Hence if the concentration of the adsorbate is less on the surface of the adsorbent than in the bulk, it is known as negative adsorption.
Explanation:
Hope this helps
what is the mass of 3.77mol of K3N?
495 g K₃N
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
3.77 mol K₃N
Step 2: Identify Conversions
Molar Mass of K - 39.10 g/mol
Molar Mass of N - 14.01 g/mol
Molar Mass of K₃N - 3(39.10) + 14.01 = 131.31 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 3.77 \ mol \ K_3N(\frac{131.31 \ g \ K_3N}{1 \ mol \ K_3N})[/tex]Multiply/Divide: [tex]\displaystyle 495.039 \ g \ K_3N[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
495.039 g K₃N ≈ 495 g K₃N
Cooling a gas in a rigid container causes
a. the container to explode
b. a decrease in pressure
c. an increase in volume
d. a decrease in the number of particles in the gas
Answer:
B
Explanation:
Presumably the system is closed (nothing can escape or enter).
A: You're cooling the container so it shouldn't explode.
C: If the container is Closed, the volume cannot increase or decrease.
D: is also impossible for the closed container reason.
B: The pressure has to decrease because the molecules are moving slower which decreases their velocity. If that happens the Force goes down.
B: Answer
Along with maintaining structure and reproduction, what is the third item that all living things face as a challenge? Question 3 options: How to socialize appropriately How to social distance effectively How to get enough sleep. How to get enough energy for daily life
Answer:
So the answer is gonna be how to get enough energy for your daily life
Explanation:
Sometimes the human body cant get enough energy from the food and protein the food gives out.
Susie wants to make lemonade on a hot summer day. She mixes lemon juice, water, and sugar in a large container. Which of the following happens as she combines the ingredients?
They mix together to form a new compound
They mix together to form a homogeneous solution
The stirring motion causes them to break down into elements
The heavier items will not completely dissolve, creating a suspension
Answer:
They mix together to form a new compound
Explanation:
I hope its correct if not I'm sorry!
am i shadow banned or something but lcan someone answer this
Answer: How many warnings have you gotten? depending on that you could've.
Explanation:
And two or more complete sentences explain how to balance the chemical equation and classify its reaction type.
__H3PO4 + __NaBr —> __HBr + ___Na3PO4
Answer:
H₃PO₄ + 3NaBr → 3HBr + Na₃PO₄
Explanation:
The unbalanced reaction expression is given as:
H₃PO₄ + NaBr → HBr + Na₃PO₄
We need to balance the expression.
Let us assign variable a, b, c and d and solve mathematically;
aH₃PO₄ + bNaBr → cHBr + dNa₃PO₄
Conserving H : 3a = c
P: a = d
O : 4a = 4d
Na: b = 3d
Br: b = c
Let a = 1, c = 3, d = 1, b = 3
So:
H₃PO₄ + 3NaBr → 3HBr + Na₃PO₄
Which statement best summarizes the relationship between volume and pressure of gasses?
A)
As one goes up, the other goes up
B)
As one goes up, the other goes down
C)
Volume and Pressure are unrelated
D)
Volume and Pressure only relate to liquids
Which property is conserved in both nuclear reactions and chemical
reactions?
A. Total number of protons and neutrons
O B. Number of atoms
C. Total mass of atoms
O D. Type of atoms
Answer:
A. Total number of protons and neutrons
Explanation:
In both nuclear reactions and chemical reactions, the total number of protons and neutrons are conserved.
It implies that the starting number of protons and neutrons in both reactions must be the same.
Chemical reactions involves, loss, gain or sharing electrons between two atoms.
Nuclear reactions deals with the nucleus of an atom.
It must be ensured that the mass and atomic number in nuclear reactions is conserved.
Answer:
Total number of protons and neutrons
Explanation:
Ap3x
(IMAGE ATTACHED)
I dont know what this is asking me, anyone know how to do this?
Answer:
Oh, you need to get the blue dots, and move them to the table or graph to plot them!
Hope that makes sense!
i have 9 protons, 10 neutrons, and 5 electrons. what is the charge of my nucleus?
Answer:
+4
Explanation:
The cell in the diagram to the right is going through a process that indicates it is a?
A-nerve cell
B-brain cell
C-blood cell
D-sex cell
NEED NOW!!
plsss help me with thiss
b) NaOH + HCl =
c) Na2O + H20 =
d) P + O2 =
e) S + O2 =
f) Na + H2O =
Lead melts at 328 ℃. How much heat is required when 23.0 g of solid lead at 297 K condenses to a liquid at 702 K?
Heat = 1.74 kJ
Further explanationGiven
melts at 328 ℃ + 273 = 601 K
mass = 23 g = 0.023 kg
initial temperature = 297 K
Final tmperature = 702 K
Required
Heat
Solution
1. raise the temperature(297 to 601 K)
c of lead = 0.130 kJ/kg K
Q = 0.023 x 0.13 x (601-297)
Q = 0.909 kJ
2. phase change(solid to liquid)
Q = m.Lf (melting/freezing)
Q = 0.023 x 23 kj/kg = 0.529 kJ
3. raise the temperature(601 to 702 K)
Q = 0.023 x 0.13 x (702-601)
Q = 0.302 kJ
Total heat = 1.74 kJ
What is the movement of water across a membrane from an area of high concentration to an area of low concentration 
Answer:
Osmosis
Explanation:
The movement of water across a membrane from an area of high concentration to that of low concentration is defined as osmosis.
Osmosis is very important in all living cells because it is one of key mechanism for transporting materials between and within cells.
The membrane most times is selectively permeable in nature and it allows for a regulated movement of materials from one region to another.
WHAT IS THE TOTAL NUMBER OF ATOMS IN BOTH OF THESE
COMPOUNDS?
Which prey is common to all owls?
Answer:
Mice
Explanation:
Small, rodent-like mammals, such as voles and mice, are the primary prey for many owl species. An owl's diet may also include frogs, lizards, snakes, fish, mice, rabbits, birds, squirrels, and other creatures. Occasionally, Great Horned Owls might even find skunks tasty enough to eat.
Please mark brainliest! I only need one more to rank up! Thank you and have a blessed day/night :D
Answer:
mice and shrews
Explanation:
i did the virtual lab on edg:)
Which has a density that is greater than 1.00 g/ml? Cole or Diet Coke?
Answer:coke
Explanation:
Coke contains more sugar making it more dense
The pictures below show samples of different substances.
The mass and volume of each sample differ from the mass and volume of the other samples. Is it possible for each sample to contain 1 mol of each substance?
A. No, because they have different masses.
B. No, because they have different volumes.
C. Yes, if each sample contains 6.02 x 1023 atoms.
D. Yes, if each sample contains 2 amu.
Answer:
C. Yes, if each sample contains 6.02 x 10²³ atoms.
Explanation:
It is possible for each sample to contain 1 mole of each sample if and only if each of the sample if made up of 6.02 x 10²³ atoms.
6.02 x 10²³ atoms is the Avogadro's number. This number is equivalent to a mole of a substance.
If the amount of matter in the given substance is at least one mole, it is possible that they are made up of one mole each of each substance. If they contain lesser amount of atoms, then it is not up to one mole of substance. But if it is greater, then, we can have even more than one mole of substance.A mole is simply a unit of measurement and it is equivalent to 6.02 x 10²³ atoms.
Answer:
Answer: C (Yes, if each sample contains 6.02 x 1023 atoms.) for all the edge speed runners ;)
Explanation:
Got it right on the test review edge 2022