Section 6 - Groups in the Periodic Table Flashcards
What is the common name given to group 1 elements?
Alkali Metals.
What are the group 1 elements in order?
Lithium, Sodium, Potassium, Rubidium, Ceasium and Francium.
What are the common properties of group 1 elements?
All of the group 1 elements have one electron in the outer shell, low melting and boiling points (compared to other metals) and they are all very soft. They are all incredibly reactive and form ionic compounds- they give up the outer electron so easily that covalent bonds are impossible.
Describe the trend between group 1 elements and reactivity. Why does this happen?
As you go down the group, the elements become more reactive, this is because the atoms get larger and the outermost electron is further from the nucleus, this means it requires less energy to remove the electron.
Describe a reaction between a group 1 element and cold water.
The element reacts vigorously with the water, producing hydrogen gas and a hydroxide of the element.
What is the common name given to group 7 elements?
Halogens.
What are the group 7 elements in order?
Fluorine, Chlorine, Bromine, Iodine and Astatine.
What are the common properties of group 7 elements?
All group 7 elements have 7 electrons in their outer shell, they all exist as diatomic molecules, sharing one covalent bond.
Describe the trend between group 7 elements and their melting and boiling points.
As you descend the group, melting and boiling points increase.
How do you test for chlorine gas?
Hold a strip of damp blue litmus paper over the gas, if it is chlorine the chlorine will bleach the litmus paper, turning it white, it may also temporarily turn red- due to chlorine solutions being acidic.
Describe the trend between group 7 elements and reactivity. Why does this happen?
As you descend the group, the elements become less reactive, this happens because a halogen only needs to gain 1 electron to complete its outer shell, as you descend the group, the atoms get larger, and the outer shell is further from the nucleus, this makes it harder to attract the electron due to the increased atomic radius.
Describe a reaction between a group 7 element and a group 1 element.
The elements react vigorously and form a salt, called a metal halide.
Describe a reaction between a group 7 element and hydrogen.
The elements react vigorously to form a hydrogen halide.
What are the properties of hydrogen halides?
They are soluble, so they dissolve in water, this produces acidic solutions.
What is a displacement reaction?
A chemical reaction that takes place in a solution where an element in a compound is replaced by a more reactive element.
