Chapter 12 - The Periodic Table Flashcards
What is the purpose of the periodic table?
Its a way of classifying the elements
In what order is the periodic table arranged?
Shows elements in order of their proton number
What is PERIODICITY?
When elements with similar properties appear at regular intervals
What are the columns called
groups
What are the rows called?
Periods
What does the group number correlate to?
Same as the number of outer-shell electrons
What are the outer-shell electrons called?
valency electrons
Why are valency electrons important?
They dictate how an element behaves
Why do elements in the same group have similar reactions?
have the same number of valency electrons
Do group 0/8 elements react?
Why?
NO
- have a very stable electron arrangement
- are unreactive
- full outer electron shell
What does the period of an element tell you?
Tells you the number of electron shells the atom has
What is the nucleon number?
Total number of particles in the nucleus
protons + neutrons
Group 1 different name
alkali metals
Group 2 different name
alkaline earth metals
Group 7 different name
halogens
Group 8/0 different name
noble gases
What percentage of the elements are metals?
over 80%
Why is hydrogen alone in the periodic table?
Properties
- has 1 valency electron
- forms a positive ion (H+)
- similar to group 1 metals but it is A GAS
- reacts like a non-metal
Revise the properties of metals and non-metals
yes
What are artificial elements and why can they not be found in nature?
- elements made in a lab
- are radioactive and their atoms break down very quickly
list the group 1 metals
lithium, sodium, potassium, rubidium, caesium, francium
list the physical properties of group 1 metals
4
- good conductors of heat and electricity
- softer than most other metals (can cut with a knife)
- low density (float on water) ctom
- low melting and boiling points ctom
ctom - compared to other metals
trends in softness g1
softness increases going down the group
trends in density g/cm3 g1
density increases going down the group
trends in melting point g1
mp decreases going down the group
trends in reactivity g1
reactivity increases going down the group
lithium reaction with water
floats and fizzes
sodium reaction with water
shoots across the water
potassium reaction with water
melts with the heat of the reaction, hydrogen catches fire producing lilac flame
Overall description of group 1 metals with water
Alkali metals react vigorously with water.
Hydrogen bubbles off, leaving solutions of their hydroxides, which are alkalis.
chemical equation of lithium/sodium with water
2Na + 2H20 –> 2NaOH + H2
2Li + 2H2O –> 2LiOH + H2
etc
Overall description of group 1 metals with chlorine
If you heat the 3 metals and plunge them into gas jars of chlorine, they burst into flames.
Burn brightly forming chlorides
Overall equation for group 1 metals with chlorine
2Li + Cl2 –> 2LiCl
2Na + Cl2 –> 2NaCl
Overall description of group 1 metals with oxygen
Burst into flames when heated and plunged into gas jars of oxygen
Form oxides
Are group 1 oxides acidic or alkaline
alkaline
- dissolve in water to form alkaline solutions