7.3

1) Atomic radius of elements is a measure by the size of its atoms typical distance from the nucleus to the boundary of the surrounding cloud of  electrons. Because heavier elements have more particles in the nucleus (number of protons and number of neutrons), the nucleus would have a stronger attractions to the electrons, which would cause the radii to be smaller.

2) Electronegativity is a measure of the ability an atom has to attract electrons to it in a bonding situation. the larger the element, the less electronegativity the element has because the electrons are further away from the nucleus, and the harder it is for these elements to bond.

3) Ionization energy is a measure of the amount of energy needed in order to rip the most loosely held valence electron away from an atom.The non-metals are harder to strip an electron away than metals because non-metals want to gain electrons, whereas metals want to loose their electrons. Also generally top right non-metals have greater number of protons and electrons in their nucleus, so they hold a better attraction to their electrons.

4)Trends are referred to being periodic because periodic means how something goes in an order/pattern and happens in certain intervals, like the Periodic Table.