Answer:
B.
Explanation:
There are the same amount of black circles in the reactant and product. There are also the same amount of white circles in the product and reactant.
The neutral atom also has 20 electrons, but to form the 2+ ion, it needs to lose 2 of these, giving just 18 electrons. A neutral calcium atom has 20 protons and so 20 electrons. A calcium ion has a 2+ charge so it has lost 2 electrons. It has 20 protons and 18 neutrons.
It was a Cambridge UK scientist in the early part of the 20 th century who discovered the electron. His name was J J Thompson.
Answer:
Ecology is the study of the relationships between animals and plants in the environment.
