Answer:
A. The air around you
Explanation:
The air around us is an example of matter, as it is a gas.
Air has no definite shape/volume and has no definite structure, so it is a gas.
Our thoughts aren't matter because they have no physical atoms, and radio waves and heat waves aren't matter either because they are forms of energy.
Seeing signs of a chemical reaction does not always mean that a reaction is happening. For example, a gas (water vapor) is given off when water boils. ... You can tell that it is a physical change because water vapor can condense to form liquid water. In a chemical change, a new substance must be produced.
Answer:
(C) Mass of KCl(s), mass of H20, initial temperature of the water, and final temperature of the solution
Explanation:
molar enthalpy of solution of KCl(s) is heat evolved or absorbed when one mole of KCl is dissolved in water to make pure solution . The heat evolved or absorbed can be calculated by the following relation.
Q = msΔt where m is mass of solution or water , s is specific heat and Δt is change in temperature of water .
So data required is mass of water or solution , initial and final temperature of solution , specific heat of water is known .
Now to know molar heat , we require mass of solute or KCl dissolved to know heat heat absorbed or evolved by dissolution of one mole of solute .
If you clear volume in the density equation:
The greater the density the lower the volume. This means, the volume of gold nugget will be smaller than the volume of iron pyrite nugget.
