Questions

We know that, there are 7 continents in the world. They are :

Asia, Africa, Australia, North America, South America, Europe and Antarctica.

Africa - 53 countries

Asia - 48 countries

Europe - 45 countries

Antarctica - 0 countries

Hence, the continent Africa has most number of countries with 53 countries and in second place Asia has 48 , third Europe has 45 countries.

Electrons orbit around the nucleus is correct about them.

Lobsters, like snails and spiders, have blue blood due to the presence of hemocyanin, which contains copper. In contrast, vertebrates and many other animals have red blood from iron-rich hemoglobin.