B.
Molten material in the earth cools and hardens to form igneous rocks.
Answer:
calcitonin
Explanation:
Calcitonin is a hormone which helps in lowering the high blood calcium levels. It is secreted by thyroid glands. Parathyroid glands are responsible for increasing calcium level in the blood while calcitonin hormone work against parathyroid glands and helps in lowering calcium level. Calcitonin hormone inhibit the activity of osteoclasts which are responsible for releasing of calcium from bones into the blood.
A covalent bond in which the electrons are shared unequally is called a(n) polar covalent bond. The atoms of the bond have partial negative and positive poles due to unequal electron distribution.
An electron exchange that results in the formation of electron pairs between atoms is known as a covalent bond. When atoms share electrons, a stable equilibrium of the attractive and repulsive forces between them is known as covalent bonding. These electron pairs are also known as shared pairs or bonding pairs. Since most interactions between carbon molecules include covalent bonds, covalent bonds are particularly significant. By sharing electrons with other molecules through covalent bonds, molecules can form extensive chains of compounds.
When atoms are distributed unevenly in a covalent connection, a polar covalent bond develops. Specifically, when the two atoms in the bond have electronegativities that range between 0.4 and 1.7. Polar covalent bonds and polar bonds are frequently used interchangeably.
To know more about Polar covalent bonds refer to: brainly.com/question/1482809
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