A phase change is when matter changes to from one state ( solid, liquid, gas, plasma) to another.
Answer:
I think its D
Explanation:
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1) Use the fact that 1 mol of gas at STP occupies 22.4 liter
=> 1 mol / 22.4 l = x / 0.125 l => x = 0.125 l * 1 mol / 22.4 l = 0.00558 mol
2) Now use the molar mass of the gas
molar mass of CO2 ≈ 44 g / mol
Formula: molar mass = mass in grams / number of moles =>
mass in grams = molar mass * number of moles = 44 g/mol * 0.00558 moles
mass = 0.246 g
Answer: 0.246 g
Matematically speaking, maybe because:
The number of substances = number of elements + number of different combinations of those elements
