the atom and stuff (10) Flashcards
1
Q
the atom
A
- has the same number of protons and electrons
- number of neutrons = mass number - protons
- atomic mass (bottom) > atomic number (top)
2
Q
calculating relative atomic mass
A
percentage of which the element occurs over 100 multiplied by its atomic mass added together
3
Q
calculating mass with amu
A
atomic mass over 12 x 1,99 x 10-26
4
Q
atomic number
A
the number of protons
5
Q
mass number
A
the total number of protons plus neutrons
6
Q
protons + neutrons
A
nucleons
7
Q
3 isotopes for hydrogen
A
protium (1:1)
deuterium (2:1)
tritium (3:1)
8
Q
group number
A
number of valence electrons
9
Q
group 1
A
alcheli metals
10
Q
group 2
A
alcheline earth metals
11
Q
group 16
A
chalkogens
12
Q
group 17
A
halogens
13
Q
group 18
A
nobel gases
14
Q
periodicity of atomic radius
A
- decreases from left to right in a given period
- increases top to bottom in a group
15
Q
melting and boiling point (with metals)
A
- increases from left to right in a period
- decreases from top to bottom in a group
