structure of an atom 2 Flashcards
1
Q
what is the relative atomic mass?
A
average mass of all isotopes of an element, taking into consideration their abundance and compared to the mass of an atom
2
Q
how does an atom become charged?
A
by gaining or losing an electron to have a full outer shell
3
Q
what are anions?
A
when an atom has gained e-
4
Q
what are cations?
A
when an atom has lost e-
5
Q
what does the electron arrangement show?
A
the distribution of e- in shells
6
Q
how are elements arranged in the PT?
A
in order of increasing atomic number
7
Q
what does the group number show?
A
the number of valence electrons
8
Q
what does the period number show?
A
the number of shells
