The Periodic Table Flashcards
Group 1 Alkaline Metals
Reactions with water
- Lithium, gas released, alkaline trail
- Sodium, melts into ball, trail, orange flame
- Potassium, ball, trail, lilac flame
metal + water -> metal hydroxide + hydrogen
2M + 2H(2)O -> 2MOH + H(2)
As you go down the group reactivity increases.
- atom radius increase (more shells)
- shielding increases
- force that holds the outer electron decreases further away from proton
- outer electron easier to lose
- reactivity increases
Group 7 Halogens
- At room temp
- Displacement reactions
- Redox reaction
- reactivity of elements
At room temp:
- Fluorine, yellow gas
- Chlorine, green gas
- Bromine, dark red liquid
- Iodine, dark grey solid
Displacement reactions:
The more reactive halogen displaces the less reactive. There is a colour change to show the reaction.
Chlorine + sodium bromide -> sodium chloride + bromine
Cl2 + 2NaBr → 2NaCl + Br2
Chlorine is gaining an electron to became a chlorine ion with a stable electronic structure. This is a reduction reaction.
Cl + e- → Cl -
OIL RIG
As you go down the group, the reactivity decreases
- When they react, they take an electron from the other substance to create a full outer shell
- The further down the further away from the pull of the nucleus
What does an atom consist of?
- central nucleus made up of protons and neutrons
- surrounded by electrons
- orbiting in shells
Relative mass/charge of
- protons
- electrons
- neutrons
Mass: Charge:
Protons: 1 +1
Neutrons: 1 0
Electrons: -1/200 -1
Atomic number
- no. of protons/electrons
- Number at top left
Mass number
- protons + neutrons
- number at bottom
What is group and period?
Group: verticals columns which can be used to predict properties and reactivity of other elements in the group
Period: horizontal rows which increases as full shells of electrons increase
Where are metals and non-metals located in the Periodic table?
Metals to the left
(From Group 3 Boron down a zig zag)
Non-metals to the right
Why do elements in the same group have similar chemical properties?
They have the same number of electrons in their outer shell
Why are noble gases unreactive?
Noble gases are unreactive because their atoms have *stable electronic arrangements + full outer shells
How do we know an element is a metal?
- They have delocalised electrons so conduct electricity
- They are alkaline
How do we know an element is non-metal?
- No delocalised electrons so doesn’t conduct electricity
- They are acidic
How are elements arranged in the Periodic table?
In order of the their atomic number (top number containing total number of protons + neutrons)
How is the electronic configuration of an element deduced?
By the number of shells and the number of electrons on those shells.
Sodium is in Period 3 and group 1: so it has an electronic configuration of 2.8.1
(2 electrons on the first shell, 8 on second and 1 on third)
