Isotopes of an element are defined has that has same atomic number but different mass number mean they have different number of neutrons
so the statement that best describe a similarity is
<span> same atomic number; different mass number
</span>so correct option is C
hope it helps
When blood calcium levels drop, glands embedded in the posterior thyroid secrete parathyroid hormone, which stimulates osteoclastic activity. It is made up of parathyroid glands that lie behind the thyroid glands. The reason why it is important because it controls calcium level in the blood and within the bones. It controlled by the low calcium levels in the blood it restorative parathyroid secretion whereas the high calcium levels in the blood stop the release of parathyroid hormone.
I think it is A
You use a bar graph instead of a line graph
