1) they have similar chemical properties.
for example fluorine from the 17th column is a non metal so does all the elements of that group.
2)they have same valence electrons in their outermost shell
example
electronic configuration of
hydrogen 1, lithium 2,1, sodium 2,8,1 and so on.
3) have same valency.
Answer:
The invention of the electron microscope allowed them to see organelles and other structures smaller than cells. There is variation in cells, but all cells have a plasma membrane, cytoplasm, ribosomes, and DNA. These similarities show that all life on Earth has a common ancestor in the distant past
Answer:option d
Explanation:Ocean acidification is the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide (CO. 2) from the atmosphere. Seawater is slightly basic (meaning pH > 7), and ocean acidification involves a shift towards pH-neutral conditions rather than a transition to acidic conditions (pH < 7).
True. <span>Hormones are chemical substances that regulate many of the body's functions. </span>Hormones are chemical substances<span>, formed in a tissue or organ, that stimulate or inhibit the growth or </span>function of other tissues or organs. They <span>work in conjunction with the endocrine, nervous, and immune systems to </span>regulate many body functions.
