Group 1 Flashcards
How are elements arranged in the periodic table?
Ordered by increasing atomic number.
Elements in the same group (column) have the
same number of outer shell electrons.
Elements in the same period (row) have the
same number of electron shells.
How many electrons are in the outer
shell of a group 1 element?
one
Why do elements in the same group have similar
chemical properties?
They have the same number of electrons
in the outer shell
What group of the periodic table are the alkali
metals?
Group 1
List two properties of alkali metals
- Relatively low melting points
- Soft
Why are group 1 elements called the alkali metals?
They react with water to form alkaline
solutions (pH greater than 7).
What are the products of the reaction between
lithium and water?
Lithium hydroxide and hydrogen
Write a balanced symbol equation for the reaction of
sodium with water
2Na + 2H2O → 2NaOH + H2 (check google if unsure)
Why should alkali metals be stored in oil?
To prevent them reacting with water
vapour and oxygen in the air.
What would be observed when lithium reacts with
water? (1)
- Slowest reaction of the alkali metals.
- Bubbles of hydrogen are produced.
- Doesn’t melt (highest melting point of alkali metals).
What would be observed when sodium
reacts with water? (3)
- Faster reaction than lithium.
- Floats on the surface of water (less dense than water).
- Bubbles of hydrogen are produced which cause the
sodium to whizz around the surface of the water. - Melts as enough energy is given out to meet sodium’s
melting point
What would be observed when potassium reacts
with water? (3)
- More violent reaction than sodium.
- Bubbles of hydrogen are produced which cause the
potassium to whizz around the surface of the water. - Melts into a shiny ball.
- Burns with a lilac flame.
What is the order of reactivity of the first 3 alkali
metals with water?
Lithium reacts least violent reaction,
potassium reacts most violently:
Lithium < Sodium < Potassium
Using the reactions of the first 3 alkali metals with
water, predict the reactivity trend down group 1
Reactivity increases down group 1
Why does reactivity increase down group 1?
- The number of electron shells increases down the group so there is more electron shielding.
- As a result, there is weaker attraction between the positive nucleus and outer shell electron.
- This means it is easier to remove an outer shell electron to form a positive metal ion.