I take it your doing the IA? If so you should have a picture of elements above the question. Oxygen is the only one labeled with 16 as the atomic mass :)
1. 12.992 L
2. 2.42 moles
3. 275.52 L
4. 567.844 g
<h3>Further explanation</h3>
Given
moles and volume at STP
Required
mass, volume and moles
Solution
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters / mol.
1. 0.58 moles ammonia :
Volume = 0.58 moles x 22.4 L = 12.992 L
2. 77.5 grams of O₂ :
Moles = 77.5 grams x (1 mol/32 grams) = 2.42
3. 12.3 mole of Bromine gas :
Volume = 12.3 mole x (22.4 L/1 mole) = 275.52 L
4. 4.8 moles iron(II)chloride :
Mass = 4.48 moles x molar mass ( 126,751 g/mol) = 567.844 g
Subtract the number of protons from the mass number.
Answer:
Electrons are particles that surround the nucleus of an atom like a cloud. As with protons and neutrons, electrons are essential to an atom's structure.
