Question

1. element a has 20 protons with 2 valence electrons, while element b has 9 protons with 7 valence electrons. which element is least reactive? 8. using the 2 bohr models below, determine which element is highly reactive.

Explanation:

Step1: Identify the elements

Element A with 20 protons is calcium (Ca). Element B with 9 protons is fluorine (F). Calcium has 2 valence - electrons and tends to lose them. Fluorine has 7 valence - electrons and tends to gain 1 electron. Generally, elements with a full outer shell (noble gases) are least reactive. Calcium is a metal and fluorine is a non - metal. Calcium is more stable than fluorine in terms of its tendency to react compared to noble gases, but among these two, calcium is less reactive as it requires more energy to lose 2 electrons compared to fluorine gaining 1 electron.

Step2: Analyze the Bohr models

The first Bohr model has 10 protons (Neon, Ne) and a full outer shell of 8 electrons. The second has 3 protons (Lithium, Li) with 1 valence electron. Lithium is highly reactive as it easily loses its 1 valence electron to achieve a stable electron configuration.

Answer:

1. Element A
2. The element with 3 protons (Lithium)