What trends are evident in atomic radius, ionization energy.....?

Moving down a group, the shielding effect increases, because the number of energy levels increases, causing more electron-electron repulsion and therefore larger radius. This larger radius means that the outer electrons are farther from the nucleus's attraction, and are therefore easier to remove, and have lower ionization energy. This also means that the weak nucleus attraction force does not attract alot of electrons, and so electronegativity also decreases.

Moving across a period, there is no shielding effect as all elements in the same row have the same number of energy levels. However, as we move across, the atomic number (number of protons in nucleus) increases, and so nucleus's attractive forces becomes stronger. This means that the outer electrons are pulled more strongly towards the nucleus, causing the radius to become smaller. This strong nucleus-electron attraction makes it harder to remove the outer electrons, so the ionization energy increases. This strong attraction also means that more electrons can be pulled towards the nucleus, so electronegativity increases.

Get a periodic desk because of this as you go from left to right/up to backside, the atomic radius scale down. Therefore, the aspect on the scale back left side has the biggest atomic radius, and the element on the upper right part has the smallest atomic radius which is hydrogen... Etc..