What is the atomic number of the atom shown?

18

Explanation:

Atomic number of an element is defined as the number of protons present in the element.

The mass number of an element is defined as the addition of the number of proton and neutron present in the element.

In the example above, the atom has a proton of 18. This signifies that the atomic number of the element is 18.

answer; ///(b) it is composed of four protein chains and four heme groups;

spiders belong to a group of arachnids.

arachnids have the following traits :

they have two body parts.

they have eight legs unlike insects which have 6 legs.

they have no wings.

these traits distinguish them from insects.

the information that antonio is doubting us the statement that spiders differences are as a result of being first to evolve.

this is because the evolution of one species is independent of the other species.