2.2/2.3 Elements, groups and organizing Flashcards
1
Q
Atomic mass
A
the weight of a single atom
measured in atomic mass units AMU
2
Q
each atom is made up of
A
proteins, neutrons, electrons
3
Q
In each box on the periodic table elements are arranged horizontally by —–
A
atomic number
4
Q
Atomic Number
A
is the number of proteins (and electrons) in the atoms nucleus
5
Q
Atomic number facts
A
the number of protiens in an atom is like the fingerprint of the atom, if you change the number of protons you change the element.
6
Q
Alkaline Metals (group one)
A
- Most reactive of the metals 2. React when exposed to air or water 3. As you move down the group reactivity increases
7
Q
Alkaline Earth Metals
A
They react when exposed to water or air but not as strong as the Alkaline metals
8
Q
Halogens (17)
A
- various colours and physical states 2. Most reactive of the non metals 3. Can combine with other metals to form new substances
9
Q
Noble gases (18)
A
- Most stable and unreactive elements 2. Long thought that they could not combine with other elements.