4. It makes the resource available for use
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]
It gives support and structure to the plant cell
1. Suzie's hypothesis (i.e. prediction of results) is that ferns which are placed in white light will grow to a taller height after two weeks than ferns which are placed in other coloured light or in a closet.
2. Her independent variable (the thing she changes to produce a result) is the kind of light that she places each plant in.
3. The dependent variable (the thing she measures) is the height of the plants after two weeks.
4. I would say her control group would be the plant placed in the closet, because every other group is exposed to some form of light.
5. I would say that Suzie has 4 experimental groups: white, red, blue, and green light.
6. The constant variables were the amount of water each plant was given, the initial height of the plants, the age of the plants, the species of fern, and what she planted the ferns in.
7. To determine how each fern did, Suzie could measure the height in addition to noting the appearance of all the plants. E.g. did any look paler than the others?
Villi increases the surface area to help with absorption and digestion. Micro-villi form a brush border that vastly increases the surface area of the plasma membrane so larger amounts of nutrients can be absorbed.
