Question

part c: application

1. why are elements in the same group similar in chemical properties?
2. if an atom has 7 protons, how many electrons does it have?
3. which element is more reactive, sodium (na) or neon (ne)? explain why.
4. explain why hydrogen (h) is placed in group 1 even though it is not a metal

Explanation:

1. Elements in the same group have the same number of valence electrons, which determines chemical - bonding behavior and thus similar chemical properties.
2. In a neutral atom, the number of protons equals the number of electrons. So, an atom with 7 protons has 7 electrons.
3. Sodium is more reactive than neon. Sodium has 1 valence electron and readily donates it to achieve a stable electron configuration, while neon has a full outer - shell (8 electrons in its outer shell) and is chemically inert.
4. Hydrogen is placed in Group 1 because it has 1 valence electron like the alkali metals in Group 1. It can lose this electron to form a + 1 ion, similar to the alkali metals, although it is a non - metal.

Answer:

1. Same number of valence electrons.
2. 7
3. Sodium (Na) is more reactive because sodium has 1 valence electron and readily donates it, while neon has a full outer - shell and is inert.
4. Because it has 1 valence electron and can form a + 1 ion like alkali metals.