\(\text{Mg}\) : There are two valence electrons in \(\text{Mg}\) atom.
⇒ Hence, the Lewis dot symbol for \(\text{Mg}\) is:
\(\text{Na}\) : There is only one valence electron in an atom of sodium.
⇒ Hence, the Lewis dot structure is:
\(\text{B}\): There are 3 valence electrons in Boron atom.
⇒ Hence, the Lewis dot structure is:
\(\text{O}\) There are six valence electrons in an atom of oxygen.
⇒ Hence, the Lewis dot structure is:
\(\text{N}\): There are five valence electrons in an atom of nitrogen.
⇒ Hence, the Lewis dot structure is:
\(\text{Br}\): There are seven valence electrons in bromine.
⇒ Hence, the Lewis dot structure is:
Find the mean and variance for the following frequency distribution.
Classes | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |
Frequencies | 5 | 8 | 15 | 16 | 6 |