The bond between two oxygen atoms (a molecule of oxygen air) has two characteristics. what are they? a. valence electrons are shared between oxygen atoms. b. a double covalent bond is formed. c. an ionic bond is formed. d. a triple covalent bond is formed.

. Valence electrons are shared between oxygen atoms.

B.A double covalent bond is formed.

Explanation: Oxygen has atomic number 8 and is come under group 6.

Number of electrons in the outer most shell are known as Valence electrons of that atom.Oxygen has 6 Valence electrons and the valency of oxygen atom is 2. That's mean it can share 2 of its electrons to form a bond.

So , total valency in O2 molecule is 4. Each of the oxygen molecule share it's 2 electrons and form double covalent bonds.

By sharing two electrons by each of the oxygen atom it's outermost shell filled and it became stable oxygen molecule ( O2 ).

the diploid number of chromosomes is sometimes represented by the symbol 2n. for the fruit fly, the diploid number is 8, which can be written as 2n = 8, where n represents twice the number of chromosomes in a sperm or egg cell.

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!