Question

if na reacts with chlorine to form nacl, which of the following elements reacts with na to form an ionic compound in a one - to - one ratio, and why?
a k, because it is in the same group as na.
b mg, because its mass is similar to that of na.
c ar, because its mass is similar to that of cl.

all the chlorides of the alkaline earth metals have similar empirical formulas, as shown in the table above. which of the following best helps to explain this observation?
a cl₂(g) reacts with metal atoms to form strong, covalent double bonds.
b cl has a much greater electronegativity than any of the alkaline earth metals.
c the two valence electrons of alkaline earth metal atoms are relatively easy to remove.
d the radii of atoms of alkaline earth metals increase moving down the group from be to ra.

Explanation:

1. For the first question, elements in the same group have similar chemical properties. Sodium (Na) is in Group 1 (alkali - metals). Potassium (K) is also in Group 1. They both have 1 valence electron and tend to form + 1 ions. When they react with non - metals like chlorine (which forms a - 1 ion), they form ionic compounds in a 1:1 ratio. Magnesium (Mg) is in Group 2 and forms a + 2 ion, so it forms compounds like MgCl₂ with chlorine. Argon (Ar) is a noble gas and is chemically inert under normal conditions.
2. For the second question, alkaline earth metals (Group 2 elements) have 2 valence electrons. Chlorine has a high electronegativity. The two valence electrons of alkaline earth metal atoms are relatively easy to remove. Chlorine gains these electrons to form Cl⁻ ions, and the metal forms M²⁺ ions, resulting in compounds with the general formula MCl₂.

Answer:

1. A. K, because it is in the same group as Na.
2. C. The two valence electrons of alkaline earth metal atoms are relatively easy to remove.