A gas has more free molecules, and it is air, not a tangible substance. Hope it helps! :)
Answer: -
2.5 moles of calcium atoms are in 2.5 moles of calcium carbonate CaCO₃
Explanation: -
In order to solve such types of problems, the first step would be to write the chemical formula of the compound.
The chemical formula of calcium carbonate = CaCO₃
The chemical symbol of Calcium is Ca.
From the formula of calcium carbonate we can see that
1 mole of CaCO₃ has 1 mole of Ca
2.5 mole of CaCO₃ has 
= 2.5 mol of Ca.
∴2.5 moles of calcium atoms are in 2.5 moles of calcium carbonate CaCO₃
That number, also known as the frequency, will be larger for a short-wavelength wave than for a long-wavelength wave. The equation<span> that relates wavelength and frequency for electromagnetic waves is: λν=c where </span>λ<span> is the wavelength, ν is the frequency and c is the speed of light.</span>
The type of energy do chemical bonds have, and the type of energy is it converted to during chemical reactions are that chemical bonds have potential energy, which is converted to heat energy during chemical reactions.
Answer: Option D
Explanation:
The chemical molecules which are bonded by atoms to form such molecule in its stable form consists of chemical potential energy. The potential energy is form of energy which is possessed by the bond, atom or molecule in its non excited or stable state.
As the chemical bonds are stable in nature, they consist of Chemical potential energy. The potential energy of bond converts into heat energy as the bond on breakage either takes up energy to break the bond or releases the heat to break the bond, during the chemical reactions occurring.
The answer is C. your Pancreas :)