Optrion A: when trying to determine a star's chemical composition.
Because unique atomic emission spectrum, analyzing the emission spectrum you can tell the chemical composition.
Answer:
The kinetic molecular theory of matter states that: Matter is made up of particles that are constantly moving. ... Molecules in the solid phase have the least amount of energy, while gas particles have the greatest amount of energy. The temperature of a substance is a measure of the average kinetic energy of the particles.
Explanation:
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Answer:

Explanation:
We can use the Ideal Gas Law to calculate the density of the gas.
pV = nRT
n = m/M Substitute for n
pV = (m/M)RT Multiply both sides by M
pVM = mRT Divide both sides by V
pM = (m/V) RT
ρ = m/V Substitute for m/V
pM = ρRT Divide each side by RT

Data:
p = 1.00 bar
M = 49 g/mol
R = 0.083 14 bar·L·K⁻¹mol⁻¹
T = 0 °C = 273.15 K
Calculation:
ρ = (1.00 × 49)/(0.083 14 × 273.15) = 2.2 g/L
The density of the gas is
.
Answer:
The change of state of wax from solid to liquid and liquid to vapors is a physical change.
Explanation:
Physical Change
The changes that occur only due to change in shape or form but their chemical or internal composition remain unchanged.
These changes were reversible.
They have same chemical property.
These changes can be observed with naked eye.
Chemical:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
These changes are irreversible
.
These changes occur due to chemical reactions.
These may not be observed with naked eye
Example
When a candle is burned, the both physical and chemical changes occur.
The solid wax is melted into the liquid and than liquid is evaporated into vapor form. It is a physical change because just the state of mater is changed. When vapors of wax are react with oxygen in air and form carbon dioxide and ash it is a chemical change which can not be reversed.