How many elements in 2NaBO3?
1
2
3
10

10

Explanation:

Take a look to the chemical compound:

Which is Sodium perborate. Its chemical composition is:

In other words it has:

One sodium atom, one Boron atom and three oxygen atoms. Therefore, it has 5 elements in total.

However, as you can see the chemical compound has a coefficient of 2, so basically the number of elements of the chemical compound is multiplied by 2:

Hence, the number of elements in is 10

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;