The answer to this question would be true.
Answer: Hydrogen and Helium
Explanation: Hydrogen is made from from one proton and one electron, making them one of the simplest forms of elements in the universe. Combining hydrogen atoms creates helium, the second most common element in the Universe.
The one that is being described above is what we call SCIENTIFIC LAW. Scientific law is what explains of what will happen every time in a certain situation. This is also different from scientific theory since scientific theory only gives an explanation to a group of happenings and this can still be modified. Hope this helps.
Answer;
The above statement is true
upon heating a copper sample will expand, leading to a lower density
Explanation;
-The density of solids decreased with increase in temperature and vice versa. The increase in temperature causes the volume of the solid to increase which as a result decreases the density as Density=Mass/Volume. The temperature of a body is the average kinetic energy of the molecules present in it.
In other words; The temperature of a body is the average kinetic energy of the molecules present in it. Therefore; when heat is supplied ( or temperature is increased) the average kinetic energy increases which increases the volume and thus density decreases.