Question

periodic table review
name:

1. as you move across a period from left to right, what happens to the number of protons in the nucleus?
2. which group on the periodic table contains the most reactive nonmetals?
3. what happens to the reactivity of alkali metals as you move down group 1?
4. which element would you expect to have properties most similar to magnesium (mg)?
5. which element is likely to have the smallest atomic radius?
6. what is the trend in ionization energy as you move down group 17 (halogens)?
7. which element in period 4 is a transition metal?
8. which factor contributes most to the increasing electronegativity across a period?
9. what is the most metallic element in group 13?

Explanation:

Step1: Recall periodic - table trends

As you move across a period from left to right, the atomic number increases. The atomic number is equal to the number of protons. So the number of protons in the nucleus increases.

Step2: Identify reactive non - metals

Group 17 (halogens) contains the most reactive nonmetals. They need only one electron to complete their outer shell.

Step3: Analyze alkali - metal reactivity

As you move down Group 1 (alkali metals), the reactivity increases. This is because the outermost electron is farther from the nucleus and easier to lose.

Step4: Find similar elements

Elements in the same group have similar properties. Magnesium is in Group 2, so calcium (Ca), which is also in Group 2, would have properties most similar to magnesium.

Step5: Consider atomic - radius trends

Atomic radius decreases across a period and increases down a group. Among common elements, helium (He) has one of the smallest atomic radii.

Step6: Determine ionization - energy trend

As you move down Group 17 (halogens), the ionization energy decreases. The outermost electrons are farther from the nucleus and easier to remove.

Step7: Identify transition metals

In Period 4, iron (Fe) is a transition metal. Transition metals are in the middle of the periodic table.

Step8: Analyze electronegativity factor

The increasing nuclear charge across a period contributes most to the increasing electronegativity. There is a stronger attraction for electrons.

Step9: Identify metallic element

In Group 13, thallium (Tl) is the most metallic element as metallic character increases down a group.

Answer:

1. The number of protons in the nucleus increases.
2. Group 17 (halogens).
3. The reactivity increases.
4. Calcium (Ca).
5. Helium (He).
6. The ionization energy decreases.
7. Iron (Fe).
8. The increasing nuclear charge.
9. Thallium (Tl).