Answer: Planet A: 76% Nitrogen, 23% Oxygen, 1% Other
Explanation: Hope this helps!
Answer:
sample B contains the larger density
Explanation:
Given;
volume of sample A, V = 300 mL = 0.3 L
Molarity of sample A, C = 1 M
volume of sample B, V = 145 mL = 0.145 L
Molarity of sample B, C = 1.5 M
molecular mass of sodium chloride, Nacl = 23 + 35.5 = 58.5 g/mol
Molarity is given as;

The reacting mass for sample A = 0.3mol x 58.5 g/mol = 17.55 g
The reacting mass for sample B = 0.2175 mol x 58.5 g/mol = 12.72 g
The density of sample A 
The density of sample B 
Therefore, sample B contains the larger density
The action force is you sitting on the chair and the reaction force is the gravity on the chair that is caused by you sitting on the chair
Answer:
135g Na2CO3
Explanation:
I'm going to assume you mean Molality which is mol solute/kg solvent
Molarity would be mol soute/ L solution
we know we have 155g of water which is .155 kg
essentially we have the equation:
mol/kg = 8.20
we substitute .155 in for kg and get:
mol/.155 = 8.20
Solving this gives mol = 1.271
now we must convert to grams using the molar mass
Molar mass Na2CO3 = 106G/mol
so to cancel moles we multiply:
1.271mol x 106g/mol
= 135g