write the formula for hydrogen and bromine forming hydrogen bromide

& nickel and oxygen forming nickel (II) oxide

H2(g) + Br2(g) ==> 2HBr(l)

2Ni(s) + O2(g) ==> 2NiO(s)

1. Hydrogen and Bromine forming Hydrogen Bromide:

The reaction equation for the formation of Hydrogen Bromide (HBr) from Hydrogen (H2) and Bromine (Br2) can be written as follows:

H2 + Br2 --> 2HBr

This equation represents the combination of two moles of hydrogen gas with one mole of bromine gas to produce two moles of hydrogen bromide.

2. Nickel and Oxygen forming Nickel (II) Oxide:

The reaction equation for the formation of Nickel (II) Oxide (NiO) from Nickel (Ni) and Oxygen (O2) can be written as follows:

2Ni + O2 --> 2NiO

This equation represents the combination of two moles of nickel metal with one mole of oxygen gas to produce two moles of nickel (II) oxide.

The formula for hydrogen and bromine forming hydrogen bromide can be derived by combining the chemical symbols and using the appropriate subscripts:

Hydrogen: H
Bromine: Br

To form hydrogen bromide, we need to balance the charges of the elements. Hydrogen has a charge of +1, while bromine has a charge of -1. In order for the overall compound to be neutral, we need to combine one hydrogen atom with one bromine atom. Therefore, the formula for hydrogen bromide is:

HBr

Moving on to nickel and oxygen forming nickel (II) oxide:

Nickel: Ni
Oxygen: O

First, we need to determine the charges of the elements involved. Nickel typically forms a 2+ cation, denoted as Ni(II), while oxygen forms a 2- anion, denoted as O(II).

To balance the charges, we need to combine one nickel(II) ion with one oxygen(II) ion:

Ni(II)
O(II)

Therefore, the formula for nickel (II) oxide is:

NiO