Question

Predict the formula of the compound formed by silicon and bromine...?

Answer 1

SiBr4 as silicon has 4 valency and bromine has 1 valency.

Answer 2

Answer: $SiBr_4$

Explanation: Silicon is an element with atomic number 14 and thus contains 14 electrons with configuration:

$Si:14:1s^22s^22p^63s^23p^2$

Thus in order to attain stable configuration. it must gain or lose 4 electrons and thus the valency is 4.

Bromine is an element with atomic number 35 and thus contains 35 electrons with configuration:

$Br:35:1s^22s^22p^63s^23p^64s^23d^{10}4p^5$

Thus in order to attain stable configuration. it must gain 1 electron and thus the valency is 1.

In order to get the formula of compound, the valencies are exchanged and thus the formula is $SiBr_4$