Answer:
B. Non-metals
Explanation:
The element with the atomic number of 17 is Cl.
Chlorine belongs to the group 7 in the periodic table. It is a non metal.
Correct option: B. Non-metals
What is a unwanted change in the environment caused by substances or from of energy??
Answer:
pollution I think
Explanation:
Isotopes are atoms of the same element that have different O principal chemical properties, masses. O numbers of protons, O numbers of electrons.
Answer:
Different atomic mass, number of neutrons
Explanation:
Isotopes refer to atoms of the same element, with same atomic number, number of protons & electrons. However, they have different atomic mass, because of different number of neutrons.