atoms, isotopes and ions. Flashcards
1
Q
what does the atomic number tell us?
A
how many protons there are in the nucleus.
2
Q
what do all atoms of an element have?
A
same atomic number.
3
Q
what does the mass number tell us?
A
number of protons and neutrons in the nucleus.
4
Q
where is the mass number usually placed on an element in the periodic table?
A
top.
5
Q
what are atoms hit by which causes them to absorb energy?
A
electrons or electromagnetic waves.
6
Q
what can atoms absorbing energy result in and what charge does it have?
A
electrons either being excited to a higher energy level or if the absorbed energy is high enough the atom can lose one or more electrons. forms a positive charged ion.
7
Q
what happens when a excited electron drops to a lower energy level?
A
emits some electromagnetic energy.
8
Q
A
