First cell theory. All living things are composed of cells.
Second cell theory. Cells are the basic unit of structure and function in living things.
Third cell theory. All cells are produced from other cells
Conception occurs when a sperm from a man fertilizes an egg from a woman. This fertilization occurs in the woman's fallopian tubes, not in her va..gina or u..terus.
Answer:
Hi there!
When dropping Alka-Seltzer into a glass of water, bubbles immediately appear and the solid substance “disappears”, dissolves, into the water. This forms a new compound, a liquid, which means a reaction took place.
Answer: The mass number of an oxygen isotope that has nine neutrons is 17 and isotope is called as Oxygen-17.
Explanation:
Atomic number is defined as the number of protons or number of electrons that are present in an atom.
For a neutral atom:
Atomic number = Number of electrons = Number of proton
Atomic number= Number of protons = 8
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons
Given: Number of neutrons = 9
Thus mass number = Number of protons + Number of neutrons = 8 + 9 = 17.
Isotopes are elements which have same atomic number but different mass number.
Thus the mass number of an oxygen isotope that has nine neutrons is 17 and isotope is called as Oxygen-17.
