This is the only non-metal element on the left side of the periodic table
What is hydrogen ?
Electrons are found here
Energy levels (or electron shells)
Elements in period 1 can have up to _____ electrons in its valence shell.
2
This group is very unreactive and has a full valence shell( (8 valence electrons )
What are the Noble gases ?
Elements in period 3 have this many energy levels
3
This is the most reactive metal
Francium (i'll also accept Cesium, Cs)
The total of protons and neutrons of an element will give you this
Atomic Mass (or mass number)
State the electron configuration of a Silicon atom.
Si: 2, 8, 4
Mendeleev arranged the periodic table using these two properties of the elements
Reactivity and mass
The atomic radius of metals _______ going up the group.
Decreases
An atom of Sodium (Na) and an atom of Sulfur (S) have this in common.
Same number of energy levels
State the electron configuration of the following cation:
Mg2+
Mg2+ : 2, 8
Arrange these elements in order of reactivity (least to most):
Ba, Mg, Sr
Mg, Sr, Ba
Describe the trend in both the atomic radius AND reactivity of halogens.
Atomic Radius: Increases going down the group
Reactivity: Gets more reactive going UP the group