Answer:
Gas, has no shape but does take up volume
N(C)=5,02·10²² atoms
calculation check:
N(C)=(1/12)*6.022*10²³=0.5018*10²³≈5.02·10²²
This is an application of Boyle's law:
P₁V₁ = P₂V₂. we don't have to convert volume and pressure to standard forms. we can even use the pressure with mmHg
1 atm = 760 mmHg
V₂ = P₁V₁ / P₂ = 745 x 500 / 760 = 490 ml
Note that here we assume constant temperature
The independent variable is the one you change, and the dependent variable is the one that changes because the independent changed (i think). The constant variable is the thing you can't change so the experiment is fair.
Independant: whatever causes the flowers to change color
Dependent: the flowers change color
Constant: same soil type, same conditions, etc.