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tresset_1 [31]
3 years ago
13

Which of the following steps in a star's life cycle takes the longest?

Chemistry
1 answer:
Vsevolod [243]3 years ago
4 0
<span>The correct anwser is "C.fusion of hydrogen atoms"</span>
You might be interested in
How many valance electrons does group #11 have?
galina1969 [7]

It would have 11 valance electrons.

Example/Explanation:

Say we are talking about groups 10. Group 10 would have 10 valance electrons because of the atom's electronic arrangement in the periodic table.

6 0
3 years ago
A substance has a volume of 10.0 cm3 and a mass of 89 grams. What is its density?
Irina18 [472]
Remembering that
d = m ÷ v

d = ?
m = 89 g
v = 10 cm³

Therefore:

d = 89 ÷ 10

d = 8,9 g÷cm³
5 0
3 years ago
Read 2 more answers
For the reaction Na2CO3+Ca(NO3)2⟶CaCO3+2NaNO3 how many grams of calcium carbonate, CaCO3, are produced from 79.3 g of sodium car
Alexus [3.1K]

Answer:

74.81 grams of calcium carbonate are produced from 79.3 g of sodium carbonate.

Explanation:

The balanced reaction is:

Na₂CO₃ + Ca(NO₃)₂ ⟶ CaCO₃ + 2 NaNO₃

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:

  • Na₂CO₃: 1 mole
  • Ca(NO₃)₂: 1 mole
  • CaCO₃: 1 mole
  • NaNO₃: 2 mole

Being the molar mass of the compounds:

  • Na₂CO₃: 106 g/mole
  • Ca(NO₃)₂: 164 g/mole  
  • CaCO₃: 100 g/mole
  • NaNO₃: 85 g/mole

then by stoichiometry the following quantities of mass participate in the reaction:

  • Na₂CO₃: 1 mole* 106 g/mole= 106 g
  • Ca(NO₃)₂: 1 mole* 164 g/mole= 164 g
  • CaCO₃: 1 mole* 100 g/mole= 100 g
  • NaNO₃: 2 mole* 85 g/mole= 170 g

You can apply the following rule of three: if by stoichiometry 106 grams of Na₂CO₃ produce 100 grams of  CaCO₃, 79.3 grams of Na₂CO₃ produce how much mass of  CaCO₃?

mass of CaCO_{3} =\frac{79.3 grams of Na_{2} CO_{3} *100 grams of of CaCO_{3}}{106 grams of Na_{2} CO_{3}}

mass of CaCO₃= 74.81 grams

<u><em>74.81 grams of calcium carbonate are produced from 79.3 g of sodium carbonate.</em></u>

6 0
3 years ago
PLEASE HELPP!!!!
Alenkinab [10]

Answer:

Na the valency electrons is 1

The ion charge is positive 1

K the valency electrons is 1

The ion charge is positive 1

Explanation:

Mg the valency electron is 2 The ion charge is positive 2

Ca the valency electron is 2 The ion charge is positive 2

Al the valency electron is 3 The ion charge is positive 3

O the valency electron is 2 The ion charge

is negative 2

F the valency electron is 1 The ion charge is negative 1

Cl the valency electron is 1 The ion charge

is negative 1

N the valency electron is 3 The ion charge is negative 3

S the valency electron is 2 The ion charge is

negative 2

3 0
3 years ago
ELETE
yKpoI14uk [10]

Answer:

5 L

Explanation:

Use Charles law and rearrange formula

Change C to K

- Hope that helped! Please let me know if you need further explanation.

6 0
3 years ago
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