Question

A neutral lithium atom has 1 valence electron. A neutral bromine atom has 7 valence electrons. A chemical reaction between the 2 forms lithium bromide.

What electrical charges would the 2 newly formed ions take on?
A. Li- and Br-
B. Li+ and Br-
C. Li- and Br+
D. Li+ and Br+

Answer 1

In a reaction to form lithium bromide, lithium becomes a Li+ ion and bromine becomes a Br- ion, which corresponds to option B.

Step-by-step explanation:

When a neutral lithium atom (Li) reacts with a neutral bromine atom (Br) to form lithium bromide (LiBr), each atom becomes an ion with a distinct charge due to the transfer of electrons. Lithium has one valence electron which it can easily lose to achieve the electron configuration of helium (He), becoming a Li+ ion with a net charge of +1. Bromine has seven valence electrons and needs one more to achieve the electron configuration of neon (Ne), and thus it gains an electron to become Br- with a net charge of -1.

The correct answer to the question is that the lithium ion takes on a charge of Li+ and the bromine ion takes on a charge of Br-, which is option B. This is consistent with the tendency of metals like lithium to lose electrons and become cations and for halogens like bromine to gain electrons and become anions.

Answer 2

Answer: Option (B) is the correct answer.

Step-by-step explanation:

Atomic number of lithium is 3 and its electronic distribution is 2, 1.

Atomic number of bromine is 35 and its electronic distribution is 2, 8, 18, 7.

It is known that a neutral atom which accepts electrons acquires a negative charge and a neutral atom that loses electrons will acquire a positive charge.

So, in order to attain stability lithium will lose its 1 valence electron and bromine will accept its 1 electron.

Therefore, lithium will acquire a positive charge and bromine will acquire a negative charge.

Thus, we can conclude that electrical charges would the 2 newly formed ions take on is
`Li^(+)` and
`Br^(-)`.