Answer:
b
Explanation:
A pure substance has a constant composition and cannot be separated into simpler substances by physical means. There are two types of pure substances: elements and compounds.
There are five states of matter out of which we encounter three states of matter in our day today life
a) gas b) solid and c) liquid
the main difference between the three is of
a) Inter molecular forces of attraction
b) thermal energy
due to this
a) solid has high intermolecular forces and low thermal energy: thus they have fix shape and occupy fix volume
b) liquid has intermediate forces and medium themal energy. Thus they may have fixed volume and but no fix shape
c) gas has weak intermoelcular forces and high thermal energy. thus they have no fixed volume no fix shape
so in the given problem
the state of the substance D- Gas.
To calculate number of moles, all you do is divide the given mass by the molecular molar mass:
<span>i.e. 125g / 18g = 6.94444g </span>
<span>Therefore, your answer is (a) 6.94 g</span>
I thinlk it's by radiation?......
This statement would be best characterized by the law of conservation of momentum—choice C.
