The smaller number is the number of protons, and the greater number is the mass.
Answer:
a) the atomic number is 15
b) the mass number is 15+16 = 31
c) element is phosphorus
d)Group 15 period 3
The law of conservation of mass dictates that the total mass of reactants must be equal to the total mass of the products. Thus:
mass(MgO) = mass(Mg) + mass(O)
mass(MgO) = 24 + 16
mass(MgO) = 40 g
The third option is correct.
Answer:
27.9 g
Explanation:
CsF + XeF₆ → CsXeF₇
First we <u>convert 73.1 g of cesium xenon heptafluoride (CsXeF₇) into moles</u>, using its<em> molar mass</em>:
- Molar mass of CsXeF₇ = 397.193 g/mol
- 73.1 g CsXeF₇ ÷ 397.193 g/mol = 0.184 mol CsXeF₇
As <em>1 mol of cesium fluoride (CsF) produces 1 mol of CsXeF₇</em>, in order to produce 0.184 moles of CsXeF₇ we would need 0.184 moles of CsF.
Now we <u>convert 0.184 moles of CsF to moles</u>, using the <em>molar mass of CsF</em>:
- Molar mass of CsF = 151.9 g/mol
- 0.184 mol * 151.9 g/mol = 27.9 g
Answer:
4.767 grams of KCl are produced from 2.50 g of K and excess Cl2
Explanation:
The balanced equation is
2 K+ Cl2 --->2 KCI
Here the limiting agent is K. Hence, the amount of KCl will be calculated as per the mass of 2.50 gram of K
Mass of one atom/mole of potassium is 39.098 grams
Number of moles is 2.5 grams = 
So, 2 moles of K produces 2 moles of KCL
0.064 moles of K will produces 0.064 moles of KCl
Mass of one molecule of KCl is 74.5513 g/mol
Mass of 0.064 moles of KCl is 4.767 grams
