They float around and they give signals
Explanation:
Melanin is the pigment which absorbs UV light and it is present in skin and gives black colour to it.As we can see africans usually have black skin as they have to face direct uv light.
Flu vaccination can help you from getting sick with flu. Vaccine reduces the risk of infection by working with body’s natural defenses to help them safely develop immunity to diseases. If you get sick, flu vaccine will make your illness milder.
Answer:
it is a category of star. our sun is a white dwarf
Explanation:
Answer:
Atoms are electrically neutral as a result of having an equal amount of positive (due to the protons) and negative (due to the electrons) charges on it.
An ion generally is an electrically unbalanced atom (i.e an atom with a net charge on it)
A negative ion called an anion is produced when an atom gains an extra electron from a neighboring atom, giving it an extra negative charge. This can be produced by ionization with a radioactive radiation or simply by dissolution.
A positive ion is called a cation and it is produced when an atom loses electron to a neighboring atom. The loss of this electron causes the positive charges to outweigh the negative charges in the atom. Cations can be produced by radioactive radiation ionization of an atom or by simple dissolution.
The subatomic particle that is negative is the 'electron'.
