Use the information below to explain why the atomic radius decreases across a period.

Detail is given below.

Explanation:

Atomic radius  trend along period:

As we move from left to right across the periodic table the number of valance electrons increases. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.

we can see in picture A there is one positive charge and force of attraction is 2.30×10⁻⁸ N

In picture D there are 2 positive charge and force of attraction is 4.60×10⁻⁸ N

So by increasing the positive charge force of attraction also increases.

In F we can see there is more positive charge thus force of attraction is also greater.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6