I would think the last one about the ozone layer
Atomic mass deals with the number of protons and neutrons added together, atomic number deals with protons only, though isotopes can be explained like this, say you had a hydrogen atom it's one proton and one electron if you add a neutron to it, the hydrogen becomes Deuterium which is a isotope of hydrogen it's the same atom just a neutron added to it for a different atomic mass if only slightly changed
Answer:
Group B elements
Explanation:
Group B metals are referred to as transition metals. They are located in the middle of the periodic table between Group IIA and Group IIIA. They provide transition between the "base formers" on the left and "acid formers" on the right.
Answer:
two atoms
Explanation:
In its stable molecular form, oxygen exists as two atoms and is written O2. to distinguish it from an atom of oxygen O, or ozone, a molecule of three oxygen atoms, O3. Even though each of these is all oxygen, combining atoms of the same element may give very different properties to the molecule.
<span>Chemical bonds are broken down in the reactants while a reaction is occurring. Products are the new chemical bonds that are formed.</span>