Answer:

Explanation:
A covalent bond involves the sharing of electrons to make the atoms more stable, and so they satisfy the Octet Rule (8 valence electrons).
Typically each atom contributes an electron to form an electron pair. This is a single bond. There are also double bonds (two pairs of electrons), triple bonds (three pairs of electrons), and coordinate covalent bonds.
Sometimes, to satisfy the Octet Rule and achieve stability, one atom contributes both of the electrons in an electron pair. This is different from other covalent bonds because usually each of the 2 atoms contributes an electron to make a pair.
The question is incomplete as it does not have the options which are:
A) anaphase
B) prophase
C) telophase
D) metaphase
E) interphase
Answer:
The correct answer will be option-D
Explanation:
Colchicine is a drug obtained from the <em>Colchicum autumnale</em> which is a poisonous European flowering plant. The drug is used to treat joint swelling and gout.
Colchicine shows its effect during the cell division cycle especially during the division of nuclear content. When the cell is in metaphase and is preparing for the anaphase, the colchicine inhibits the polymerisation of the microtubules. The inhibition of microtubules inhibits the assembly of the mitotic spindle as a result of this the DNA do not move into new daughter cells.
Thus, option-D is the correct answer.
1st and 4th options are suitable answers, as these 2 changes are not exactly physical changes as it cant return back to original form and as well as its not cooling, so I feel its 1st and 4th options
Calcium has the least attraction for electrons in a chemical bond