Answer:
fossil evidence
fit of South America and Africa
Explanation: can i have brainlist please
What was Bohr's model of the atom?
Answer:
In atomic physics, the Bohr model or Rutherford–Bohr model, presented by Niels Bohr and Ernest Rutherford in 1913, is a system consisting of a small, dense nucleus surrounded by orbiting electrons—similar to the structure of the Solar System, but with attraction provided by electrostatic forces in place of gravity.
Explanation:
Answer:
In atomic physics, the Bohr model or Rutherford–Bohr model, presented by Niels Bohr and Ernest Rutherford in 1913, is a system consisting of a small, dense nucleus surrounded by orbiting electrons—similar to the structure of the Solar System, but with attraction provided by electrostatic forces in place of gravity
During photosynthesis the chemical bonds between are broken
Answer:
yes they are broken down into smaller units
When plant cells make food, they transform________________ into ________________
Answer:
Carbon dioxide into energy
Explanation:
Plants are autotrophs and prepare their own food through the process of photosynthesis. During the process of photosynthesis, plants utilizes, carbon dioxide and water in the presence of sunlight and produce energy and oxygen.
Plants cell during photosynthesis, uses carbon dioxide and transform it into energy in the form of glucose and releases oxygen.
Hence, the correct answer is "Carbon dioxide into energy".
What is the name of the piece of paper at the end of a chromatography experiment?
Answer:
There are two phases involved in chromatography; the 'stationary phase', in this case the paper, and the 'mobile phase', the salt solution. Sort the 'Smarties' into piles of the same colour.
Explanation:
If a concentrated solution of acetic acid is 99.5 % HC 2 H 3 O 2 and has a density of 1.05 g/mL, what is the concentration of this acid in moles per litre?
The concentration of this acid in moles per litre : 17.41
Further explanationGiven
99.5% acetic acid
density=ρ=1.05 g/ml
Required
the concentration (mol/L)
Solution
99.5% dan density 1.05 g/ml (MW acetic acid = 60 g/mol)
[tex]\tt 99.5\%\times 1.05\dfrac{g}{ml}\times \dfrac{1000~ml}{L}=1044.75~g/L\\\\\dfrac{1044.75~g/L}{60~g/mol}=17.41~mol/L[/tex]
1. List the types of fronts found on this map
Answer:
Cold Front. A side view of a cold front (A, top) and how it is represented on a weather map (B, bottom). ...
Warm Front. ...
Stationary Front. ...
Occluded Front.
Giving brainliest please help with this question
Answer:
B
Explanation:
Is oatmeal cookie an element compound or mixture
Answer:
oatmeal with raisins is a heterogeneous mixture. The raisins may be solid, but turn the bowl over and you will see the mixture as a whole most definitely acts like a liquid. Mud puddles are a heterogeneous mixture.
Explanation:
Answer:
An oatmeal cookie is a heterogeneous mixture, which contains multiple distinct components
If more of a liquid evaporates,does that mean it has stronger intermolecular forces
Answer:
No
Explanation:
The stronger the intermolecular forces the molecules tend to stay in the liquid phase. Compounds with weak intermolecular forces are more volatile and more molecules overcome those forces to pass to the gas phase.
How many moles of nitrogen are in 9.82x10^23 formula units of nitrogen? Please show work!
Answer:
1.63 mols
Explanation:
to convert mols to formula unit, or formula unit to mols, u need the avagadros number which is 6.022*10^23 and the number of mols/formula units
so since the given is formula units, u just have to divide the number by 6.022*10^23 to get the amount of mols
9.82*10^23 / (6.022*10^23) = 1.63 mols
*be careful for sig figs
Wass, volume and density are all properties of
matter
3
weight.
formula
Answer:
:)
Explanation:
They are all properties of Matter. weight and formula wouldn't make sense.
which term refers to the condition that exists when no over all change in concentration results from diffusion?
a. concentration
b. osmosis
c. equilibrium
d. randomness
Answer:
a.cocentration es la respuesta
____ NaBr + ____ Ca(OH)2 ___ CaBr2 + ____ NaOH
Answer:
2 NaBr + 1 Ca(OH)2 ---> 1 CaBr2 + 2 NaOH
what is the answer pls help me
Answer:fist one 2 and 3 next
Explanation:
i looked it up
Balance the following equations
Al + Cl2 AlCl3
Ag2O + Be Ag + BeO
K + O2 K2O
CoP + NaBr CoBr3 + Na3P
Si + Hg2S SiS2 + Hg
Li + Ni3N2 Li3N + Ni
Ca + K3N --> Ca3N2 + K
SnS2 + F2 --> SnF4 + S
Answer:
Explanation:
2Al + 3Cl2 --> 2AlCl3
Ag2O + Be -----> 2Ag + BeO
4K + O2 ---> 2K2O
CoP + 3NaBr ---> CoBr3 + Na3P
Si + Hg2S ---> SiS2 + Hg
6Li + Ni3N2 --- > 2Li3N + 3Ni
3Ca + 2K3N --> Ca3N2 + 6K
SnS2 + 2F2 --> SnF4 + 2S
A group 2 metal carbonate has a mass of 84 g/mol. Identify the group 2 metal X using its chemical formula.
Please show your working out. number of moles in 0.3g of calcium carbonate.
Answer:
Magnesium
0.003mole
Explanation:
The problem here entails we find the metal in the carbonate.
For group 2 member, let the metal = X;
The carbonate is XCO₃;
If we sum the atomic mass of the elements in the metal carbonate, we should arrive at 84g/mol
Atomic mass of C = 12g/mol
O = 16g/mol
Atomic mass of X + 12 + 3(16) = 84
Atomic mass of X = 84 - 60 = 24g/mol
The element with atomic mass of 24g is Magnesium
B.
Number of moles in 0.3g of CaCO₃:
Molar mass of CaCO₃ = 40 + 12 + 3(16) = 100g/mol
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Number of moles = [tex]\frac{0.3}{100}[/tex] = 0.003mole
Which of the following statements best describes how metamorphic rock was formed?
A. Low temperature and low pressure may transform an igneous rock into a metamorphic rock with banded layers.
B. High temperature and intense pressure may transform an igneous rock into a metamorphic rock with banded layers.
C. Low temperature intense pressure may transform a sedimentary rock into a metamorphic rock with banded layers.
Answer:
High temperature and intense pressure may transform an igneous rock into a metamorphic rock with banded layers.
Explanation:
A metamorphic rock is formed under high temperature and intense pressure may transform an igneous rock into a metamorphic rock with banded layers.
An igneous rock is often formed when molten magma erupts from the earth's crust. The molten magma is usually very hot but cools off with time to form a solid mass.
This rock that was first formed eventually gets transformed in the course of time as it is acted upon by high temperature and intense pressure which gradually transforms the igneous rock into a metamorphic rock with banded layers.
Learn more: https://brainly.com/question/19930528
How many molecules of Mg3N2 (magnesium nitride) are formed when excess Mg (magnesium)
reacts with 24.3 moles of N2 (nitrogen gas)?
3Mg(s) + N2(g) → Mg3N2(s)
Please explain or show how to work it as well!
Explanation:
3Mg(s) + N2(g) = Mg3N2(s)
First check that the equation is balanced. In this case, it is.
Assuming that magnesium is the limiting reactant:
First find the molecular weight using the Periodic Table.We find that the atomic mass of magnesium is approximately
24.3g, so the molecular weight is just 24.3g\mol
2. Next we need the mole to mole ratio. As there are 3
magnesiums for 1 magnesium nitride (shown by the coefficients), the
mole to mole ratio is 1 mol Mg3N2\3 mol Mg.
3. We need the amount of the substance, in grams. Since you have not
stated it in the question, I'll just do 10g AS AN EXAMPLE. Note that
depending on the amount, the LIMITING REAGENT MAY DIFFER.
4. Finally, we need the molecular weight of Mg3N2, which we can easily
calculate to be around 100.9\mol.
5. Putting this all together, we have 10gMg⋅ (mol Mg\24.3gMg)
(1mol Mg3N2\ 3mol Mg) (100.9g Mg3N2\mol Mg3N2)
the units will cancel to leave gMg3N2 (grams of magnesium nitride):
10gMg ⋅ (mol Mg\24.3gMg) (1mol Mg3N2\3mol Mg)
(100.9g Mg3N2\mol Mg3N2)
Doing the calculation yields approximately 13.84g.
Assuming that nitrogen is the limiting reactant:
Similarly, following the above steps but with 10g of nitrogen yields 36.04g
In conclusion, as we produce less amount of Mg3N2 when we assumed that Mg was the limiting reagent, magnesium is the limiting reagent and nitrogen is the excess.
Note: This is in THIS CASE, where we have 10g of both. The answer may vary depending on the amount of each substance.
Answer:
1.46×10^25 molecules
Explanation:
Each mole of N₂ reacts with 3 moles of Mg to form 1 mole of Mg₃N₂. That is, the number of moles of product is equal to the number of moles of nitrogen gas when excess magnesium is present.
There are 6.022×10²³ molecules in each mole of a substance, so the number of molecules of Mg₃N₂ is
(24.3 mol)(6.022×10²³ molecules/mol) = 1.46×10²⁵ molecules
Some metal chips with a total volume of 3.29 cm3 are placed on a piece of paper and weighed. The combined mass is found to be 18.43 g, and the paper itself weighs 1.2140 g. Calculate the density of the metal to the proper number of significant figures.
Answer:
d = 5.23 g/cm³
Explanation:
Given data:
Volume of metal chips = 3.29 cm³
Mass of metal chips and paper = 18.43 g
Mass of paper = 1.2140 g
Density of metal = ?
Solution:
Mass of metal = combined mass - mass of paper
Mass of metal = 18.43 g - 1.2140 g
mass of metal = 17.22 g
Density:
d = mass/ volume
d = 17.22 g/ 3.29 cm³
d = 5.23 g/cm³
a student finishes an experiment and is left with three empty beakers that held liquids during the experiment .the best lab practice is to
Answer:
Rinse With distilled water
which of the two metal ions mg2+ and zn2+ is the most reactive why?
Answer:
Mg2+
Explanation:
The most reactive ions from the given choices is the magnesium ion. This is because it is higher in the activity series of metals.
Zinc ion is below this specie in the activity series.
As a rule, ions above another on the activity series are generally more reactive than those below.
From any solution, magnesium ion will displace the zinc ion in such process.
The position of metallic ions determines their reactivity.
A scientist was working in a nuclear reactor facility and was exposed to radioactive particles. Although the scientist was wearing only basic clothing as protection, she exhibited no symptoms of radiation poisoning. What type of radiation was the scientist most likely exposed to?
Group of answer choices
A. Beta
B. Gamma
C. Alpha
D. None of the above
Answer:
C. Alpha
Explanation:
In a nuclear reactor facility, radioactive decay takes place, which is any several processes by which unstable nuclei emit subatomic particles and ionizing radiation and disintegrate into one or more smaller nuclei. A scientist working under this condition is likely to be exposed to alpha particles because it contains a minimal absorption range and they are the least dangerous regarding external exposure.
If 5.4 moles of Fe react with 4.7 moles of O2, what is the maximum amount of Fe2O3 (in moles) that can be produced? What is the limiting reactant?
a
3.1 moles of Fe2O3 is the maximum amount that can be produced. Oxygen is the limiting reactant.
b
2.7 moles of Fe2O3 is the maximum amount that can be produced. Iron is the limiting reactant.
c
7.1 moles of Fe2O3 is the maximum amount that can be produced. Oxygen is the limiting reactant.
d
10.8 moles of Fe2O3 is the maximum amount that can be produced. Iron is the limiting reactant.
Answer:
2.7 moles of Fe₂O₃ is the maximum amount that can be produced. Iron is the limiting reactant.
Explanation:
The balanced reaction is:
4 Fe + 3 O₂ → 2 Fe₂O₃
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
Fe: 4 molesO₂: 3 molesFe₂O3: 2 molesThe limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.
You can use a simple rule of three as follows: if by stoichiometry 4 moles of Fe reacts with 3 moles of O₂, how much moles of Fe will be needed if 4.7 moles of O₂ react?
[tex]moles of Fe =\frac{4. moles of Fe*4.7 moles of O_{2}}{3 moles of O_{2} }[/tex]
moles of O₂= 6.27
But 6.27 moles of Fe are not available, 5.4 moles are available. Since you have less moles than you need to react with 4.7 moles of O₂, iron Fe will be the limiting reagent.
So you can use a simple rule of three as follows: if by stoichiometry 4 moles of Fe produce 2 moles of Fe₂O₃, how many moles of Fe₂O₃ will be produced if 5.4 moles of Fe react?
[tex]moles of Fe_{2}O_{3}=\frac{5.4 moles of Fe*2 moles of Fe_{2} O_{3} }{4 moles of Fe}[/tex]
moles of Fe₂O₃= 2.7 moles
Then:
2.7 moles of Fe₂O₃ is the maximum amount that can be produced. Iron is the limiting reactant.
3. A 240 mL sample of argon gas at 270 K is cooled until the volume is 180 mL. What is the new temperature?
Answer:
202.5 K
Explanation:
Calculate the empirical formula of each of the following substances with the following compositions.
a 3.60 g of magnesium and 10.65 g of chlorine
b 9.1 g of lithium and 10.4 g of oxygen
Explanation:
Note: Molar masses of elements can be found online or in the periodic table.
Moles of Magnesium
= 3.60g / (24.3g/mol) = 0.148mol.
Moles of Chlorine
= 10.65g / (35.45g/mol) = 0.300mol.
Mole ratio of Magnesium to Chlorine
= 0.148mol : 0.300mol = 1 : 2.
Hence we have the empirical formula MgCl2.
Moles of Lithium
= 9.1g / (6.94g/mol) = 1.311mol.
Moles of Oxygen
= 10.4g / (16g/mol) = 0.650mol.
Moles ratio of Lithium to Oxygen
= 1.311mol : 0.650mol = 2 : 1.
Hence we have the empirical formula Li2O.
Please help: A 0.200 M NaOH solution was used to titrate a 18.25 mL HF
solution. The endpoint was reached after 31.20 mL of titrant
were added. Find the molar concentration of the original HF
solution.
The molar concentration of the original HF solution : 0.342 M
Further explanation
Given
31.2 ml of 0.200 M NaOH
18.2 ml of HF
Required
The molar concentration of HF
Solution
Titration formula
M₁V₁n₁=M₂V₂n₂
n=acid/base valence (amount of H⁺/OH⁻, for NaOH and HF n =1)
Titrant = NaOH(1)
Titrate = HF(2)
Input the value :
[tex]\tt 0.2\times 31.2\times 1=M_2\times 18.25\times 1\\\\M_2=0.342[/tex]
modern atomic theory is on_____including Dalton's atomic theory and quantum mechanics, Modern atomic theory is built on es -)) A) Bohr B) nuclear C) plum pudding D) previous models
Answer:
D) Previous models
Got it right on USTestPrep
Answer:
previous models
Explanation:
I did it
Once we use up all the nonrenewable Energy sources they cannot be replenished.
O True
O False
Answer:
true
Explanation:
it says none renewable so you can't reuse it
Answer:
false
Explanation:
becuase nonrenewable means it can not be replenished
Uranium contains two isotopes, U-235 with an atomic mas of 235 g/mol, and u-238 with an atomic mass of 238g/mol. U-235 is needed
as a fuel in nuclear reactors. Until recently, the method used to separate U-235 from U-238 was by gas diffusion. Use U-235 as R1, and
U-238 as R2 and determine the rate of diffusion and which gas will diffuse faster.
⚪︎U-235 diffused 10.01 times faster than U-238
⚪︎U-235 diffused 1.01 times slower than U-238
⚪︎U-235 effused 2.01 times slower than U-238
⚪︎U-235 effused 1.01 times faster than U-238
⚪︎U-235 diffused 1.01 times faster than U-238
Answer:
the answer is in the image
Explanation:
Question 8 (1 point)
Use coefficients to balance the following reaction:
H2CO3 + Fe → Fe2(CO3)3 + H2
Blank 1:
Blank 2:
Blank 3:
Blank 4:
Answer:
1) 3 2) 2 3) 1 4) 3
Explanation:
so on the reactant side (left), there is 2 H, 1 CO3, and 1 Fe. On the product side (right) there is 2 Fe, 3 CO3, and 2 H2. So to start I added a 3 in the first blank to make CO3 equal on both sides. In doing this, there is not 2 H, there is now 6 so I added a 3 in the 4th blank. Currently, H and CO3 are equal on both sides but not Fe. So I added a 2 in the 2nd blank. I didn't add anything in the 3rd blank so it is an understood 1.
The balanced equation
3H₂CO₃ + 2Fe → Fe₂(CO₃)₃ + 3H₂
Further explanationGiven
Reaction
H₂CO₃ + Fe → Fe₂(CO₃)₃ + H₂
Required
Coefficient of the reaction
Solution
Give a coefficient(the most complex = 1)aH₂CO₃ + bFe → Fe₂(CO₃)₃ + cH₂
Make an equationPrioritize balancing the elements that form the most complex compounds
Fe, left = b, right = 2⇒b=2
C, left = a, right = 3⇒a=3
H, left = 2a, right = 2c⇒2a=2c⇒2.3=2c⇒6=2c⇒c=3
The equation becomes :
3H₂CO₃ + 2Fe → Fe₂(CO₃)₃ + 3H₂