<span>A scientific theory summarizes a hypothesis or group of hypotheses that have been supported with repeated testing.A scientific theory is a well-substantiated
explanation of some aspect of the natural world, based on a body of
facts that have been repeatedly confirmed through observation and
experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world.</span>
Answer:
metamorphic-existing rocks are exposed to extreme conditions
sedimentary rock-layers of sediment dry together
igneous rock-magma or lava cools and solidifies.
Explanation:
Answer:
The mass number (symbol A, from the German word Atomgewicht [atomic weight]),[1] also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. It is approximately equal to the atomic (also known as isotopic) mass of the atom expressed in atomic mass units. Since protons and neutrons are both baryons, the mass number A is identical with the baryon number B as of the nucleus as of the whole atom or ion. The mass number is different for each different isotope of a chemical element. Hence, the difference between the mass number and the atomic number Z gives the number of neutrons (N) in a given nucleus: N = A − Z.[2]
The mass number is written either after the element name or as a superscript to the left of an element's symbol. For example, the most common isotope of carbon is carbon-12, or 12
C
, which has 6 protons and 6 neutrons. The full isotope symbol would also have the atomic number (Z) as a subscript to the left of the element symbol directly below the mass number: 12
6C
.[3]
Answer:
Central
Explanation:
The central nervous system.
