Nucleophilic substitution — excess ammonia

Step 1 of 2

1. 1.The nitrogen lone pair attacks the δ+ carbon.
2. 2.The C–Br bond breaks heterolytically towards bromine.

An ethylammonium ion (CH₃CH₂NH₃⁺) forms — note the + on nitrogen — plus Br⁻.

Step 2 of 2

1. 1.A second ammonia acts as a base, using its lone pair to remove a proton from N⁺.
2. 2.The N–H bonding pair collapses back onto nitrogen, neutralising the positive charge.

Ethylamine forms; NH₄⁺ (with Br⁻, ammonium bromide) is the by-product.