Atomic mass Calcium = 40.078 a.m.u
40.078 g ---------------- 6.02x10²³ atoms
165 g -------------------- ??
165 x ( 6.02x10²³) / 40.078 => 2.47x10²⁴ atoms
hope this helps!
Answer:

Explanation:
We will need a balanced equation with masses, moles, and molar masses, so let’s gather all the information in one place.
Mᵣ: 44.01
C₃H₈ + 5O₂ ⟶ 3CO₂ + 4H₂O
n/mol: 1.5
1. Calculate the moles of CO₂
The molar ratio is 3 mol CO₂:1 mol C₃H₈

2. Calculate the mass of CO₂.

0.086mole
Explanation:
The problem is very simple. It involves conversion from mass to number of moles of NaCl
What is mole?
A mole is a unit of measuring chemical substances. It is the amount that contains the avogadro's number of particles.
How is it related and can be converted from mass;
Number of moles of a substance = 
Since we know the mass, we can find the molar mass and put into this equation;
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Number of moles of NaCl =
0.086mole
learn more:
Number of moles brainly.com/question/1841136
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Answer:
A synthesis reaction is <em>a reaction that occurs when two or more reactants combine into one product.</em>
Explanation:
A reaction that occurs when two or more reactants combine into one product is called a synthesis reaction.
A reaction that occurs when one element within a compound is exchanged with another element is called a single replacement reaction.
A reaction that occurs when a substance combines with molecular oxygen, releasing light and energy is called combustion.
A reaction that occurs when a single substance breaks apart and forms two or more new substances is called decomposition.