Notes

-Group 0 contains non-metal elements placed in a vertical column on the far right of the periodic table. The elements in group 0 are called Noble gases. They exist as single atoms.

-The noble gases have low boiling points, helium has the lowest boiling point of any element

https://bam.files.bbci.co.uk/bam/live/content/zsxfk2p/large <--- Graph that shows the boiling point of Noble gases (Group 0) going down the higher you go up in the group.

Xenon- -110 (Highest boiling point in Group 0)
Krypton- -155
Argon- -185
Neon- -245
Helium- -270 (Lowest boiling point in the entire periodic table)

Going down group 0;
-The atoms become larger
-Forces between atoms become stronger
-More energy is needed to overcome these forces

Question
Radon is situated below xenon in group 0. Predict the likely boiling point of radon.

My answer: -130
The answer: The actual boiling point of radon is -61.7˚C. An estimate would lie midway between -100˚C and -50˚C based on the shape of the graph.
"Below" may just mean above when it either comes to negative numbers or just in general in types of questions like these.

An elements group number is the same of the amount of electrons it has in its outer shell. Noble gases have a full outer shell of electron. Elements in a same group all react similar ways.
Group 1 metals are called the alkali metals, they are soft, shiny when freshly cut, tarnish quickly and they are extremely reactive. The reactivity increases when you go down the group.

When group 1 atoms react they lose their 1 electron and they become a positive ion.
As you go down group 1, the atoms have more shells of electrons which means the outer electron gets further away from the positive nucleus, which makes the atom more reactive.

The atoms of group 7 have 7 electrons in their outer shell, they share one with another atom to form molecules. In reactions, each atom gains an electron to complete its outer shell, forming a negative ion. As you go down group 7, the reactivity of the element decreases, the atoms have more filled electron shells so the outer-most shell gets further from the positive nucleus so its more difficult to attract and gain electrons.

The products of the reaction of sodium and water are sodium hydroxide and hydrogen. Sodium hydride and oxygen cannot be made in this reaction.
The group 1 elements have low melting points compared to other elements. They have low densities, which explains why some of them float on water.
The product of the reaction with chlorine is a white solid at room temperature. Chlorine is a green gas at room temperature.

Group 0 elements are unreactive because they have stable electronic structures.
The equation for the reaction of iron and chlorine to make iron(III) chloride is 2Fe + 3Cl2 → 2FeCl3.
As the molecules get larger, their boiling points increase.