In which of the following cases does an atom have a positive charge?

a. there are more electrons than neutrons.
b. there are more protons than electrons.
c. there are more electrons than protons.
d. there are more neutrons than electrons.

B. There are more protons than electrons.

Explanation:

When the number of protons is greater than that of the electrons, such an atom becomes positively charged.

An atom is made up of three main subatomic particles which are the protons, neutrons and electrons.

The electrons are negatively charged particles that moves round a central nucleus in an atom. They occupy the bulk of the volume in an atom. They are considered weightless relative the nucleons ie protons and neutrons.

The protons and neutrons are massive particles that occupy a tiny centre region in an atom. They are called nucleons and this is where the bulk of the mass of an atom concentrates. Protons have positive charges on them whereas neutrons have no charge on them.

In a neutral atom, the number of protons and electrons are thesame. Here, the positive charges cancels out the negative charges.

For a cation which is a positively charged ion, the number of protons are greater than the number of electrons. A cation must have lost an electron to have tripped the balance.

For anions which are negatively charged ions, the number of electrons are greater than those of protons.

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation