Question

Using only the information available in the periodic table, consider the elements potassium and bromine. From their location on the periodic table, identify the oxidation state and number of valence electrons for potassium and bromine. Then use this information to describe their reactivity.

Which statement most accurately describes the compound formed by potassium and bromine?
A) Potassium and bromide form an ionic compound called potassium bromide (KBr).

B) Potassium and bromide form an ionic compound called potassium bromide (K2Br).

C) Potassium and bromide share electrons to form a covalent compound called potassium monobromide (KBr).

D) Potassium and bromide share electrons to form a covalent compound called potassium dibromide (KBr2).

Answer 1

The answer to your question is: letter A

Step-by-step explanation:

Potassium Is in group IA Valence electrons = 1

Bromine Is in group VIIA Valence electrons = 7

A) Potassium and bromide form an ionic compound called potassium bromide (KBr).

B) Potassium and bromide form an ionic compound called potassium bromide (K2Br).

C) Potassium and bromide share electrons to form a covalent compound called potassium monobromide (KBr).

D) Potassium and bromide share electrons to form a covalent compound called potassium dibromide (KBr2).

Answer 2

A) Potassium and bromide form an ionic compound called potassium bromide (KBr)

Step-by-step explanation:

We are to identify the oxidation state and Number of electrons.

But what are oxidation state and valence electrons?

The oxidation state, sometimes referred to as oxidation number, describes the degree of oxidation of an atom in a chemical compound. It is a number assigned to an element in chemical combination which represents the number of electrons lost (or gained, if the number is negative), by an atom of that element in the compound.

Valence Electrons on the other hand, refers to the number of electrons in its outermost shell.

Potassium (K) belongs to group 1 and Bromine (Br) belongs to group 7.

In the modern periodic table, elements in the same groups, have the same number of outermost electrons.

This means Valency of K = 1 and valency of Br = 7

Potassium can only lose one electron hence it's oxidation state = +1

Bromine would gain lose one electron hence it's oxidation state = -1

Potassium and Bromine would form an ionic bond due to the transfer of one electron by K and acceptance of one electron by Br. The compound formed is potassium bromide (KBr).