Well partly yes because air pollution can happen when we burn fossil fuels, it can happen when we use vehicles and household/farming chemicals can cause air pollution so yes it is caused by humans
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.
Each water molecule consists of two atoms of the element hydrogen joined to one atom of the element oxygen. An interesting property of water is the ability of its molecules to “stick together.” This occurs because one side of each water molecule is slightly negative and the other side is slightly positive. The positive portion of a water molecule is attracted to the negative portion of an adjacent water molecule. As a result, water molecules are called polar molecules. They attract other water molecules like little magnets. It is most likely ionic bonding but between hydrogen and oxygen it is covalent.
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B) O^2-
Hope this helped :)