Answer:
B. an element
Explanation:
An atom is smallest indivisible particle that takes part in a chemical reaction. Different atoms due to the number of their protons called atomic number gives an element. Every element is a singular atom on it's own. Combination of atoms leads to the formation of molecules and compounds.
When compounds mix together without an actual chemical change, a mixture forms.
Elements are distinct substances that cannot be split up into simpler substances. They are usually made up of only one kind of atom.
Answer: The molar mass of each gas
Explanation:
Mole fraction is the ratio of moles of that component to the total moles of solution. Moles of solute is the ratio of given mass to the molar mass.

Suppose if there are three gases A, B and C.
a) 
b) 
c) 
moles of solute =
Thus if mass of each gas is known , we must know the molar mass of each gas to know the moles of each gas.
Answer:
im not sure but I hope this helps
Explanation:
I believe the equivalents is just the moles reactant/moles limiting reactant
water has a denisty of 1 g/mL. 1 L is 1000 ml so there are 1000g/L.
the molar mass of water is 18g/mol if you use the Liters in the equation above you can find the number of grams present. divide this number you found by 18 to find the moles.
now take the amount of the other reactant given and divide it by its own molar mass. this will give you the number of moles of that reactant.
divide the moles of water by the moles of the reactant and that is the equivalent.
to find the normality you take this number and divide it by the number of liters.
D = 0.2 g / ml = 0.2 g / cm³
For example, density of steel is 7.85 g / cm³.
Density of pure water is 1.0 g/cm³. An object which has a density < 1.0 g/cm³ will float in water.
Answer: Material that has a density of 0.2 g/ml ( 0.2 g/cm³ ) is good for making couch cushions.
Answer:
Any characteristic that can be determined without changing the substance's chemical identity. chemical property: Any characteristic that can be determined only by changing a substance's molecular structure
Explanation: