Biology Final Chapter 2

2.

A sulfur atom has 6 electrons in its third shell, which is its outer shell. As a result, it forms _______ covalent bonds with other atoms.

Explanation
A sulfur atom has 6 electrons in its outer shell, which means it needs 2 more electrons to achieve a stable octet configuration. Therefore, it forms two covalent bonds with other atoms, sharing 2 electrons with each atom to complete its outer shell.

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3.

Explain what a polar molecule is

Is slightly negative at one end and slightly positive at the other
Has an extra electron, giving a positive charge
Has an extra electron, giving a negative charge
Has covalent bonds

Correct Answer

A. Is slightly negative at one end and slightly positive at the other

Explanation

A polar molecule is one in which the distribution of electrons is uneven, resulting in a slight negative charge at one end and a slight positive charge at the other. This occurs when there is a significant difference in electronegativity between the atoms involved in the covalent bond. The more electronegative atom attracts the shared electrons more strongly, causing a partial negative charge, while the less electronegative atom has a partial positive charge. This polarity allows polar molecules to interact with other polar molecules or ions through attractions known as dipole-dipole interactions.

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4.

Which of the following elements is least abundant in your body

Carbon
Oxygen
Phosphorus
Iron

Correct Answer

A. Iron

Explanation

Iron is the least abundant element in the human body. While carbon, oxygen, and phosphorus are essential elements found in various molecules throughout the body, iron is present in much smaller quantities. Iron is primarily found in hemoglobin, the protein in red blood cells responsible for carrying oxygen, and in enzymes involved in various metabolic processes. Although iron is crucial for several physiological functions, its overall concentration in the body is lower compared to carbon, oxygen, and phosphorus.

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1

5.

Which of the following are compounds

Mgci2
H2
Fe
C2h6

Correct Answer(s)

A. Mgci2
A. C2h6

Explanation

The compounds in the given options are mgci2 and c2h6. MgCl2 is a compound because it consists of two elements, magnesium (Mg) and chloride (Cl), combined in a fixed ratio. C2H6 is also a compound, known as ethane, which consists of two elements, carbon (C) and hydrogen (H), combined in a fixed ratio. On the other hand, H2 and Fe are not compounds. H2 is a diatomic molecule of hydrogen, and Fe is a single element, iron.

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6.

At atom can be changed into an ion by adding or removing______. an atom can be changed into a different isotope by adding or removing_. But if you change the number of ______, the atom becomes a different element.

Correct Answer(s)
elements, protons, nuetrons

Explanation
An atom can be changed into an ion by adding or removing electrons. An atom can be changed into a different isotope by adding or removing neutrons. But if you change the number of protons, the atom becomes a different element.

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Biology Final Chapter 2

Which of the following is not a chemical reaction

Quiz Preview

A sulfur atom has 6 electrons in its third shell, which is its outer shell. As a result, it forms _______ covalent bonds with other atoms.

Explain what a polar molecule is

Which of the following elements is least abundant in your body

Which of the following are compounds

At atom can be changed into an ion by adding or removing______. an atom can be changed into a different isotope by adding or removing_. But if you change the number of ______, the atom becomes a different element.

Biology Final Chapter 2

Which of the following is not a chemical reaction

Quiz Preview

A sulfur atom has 6 electrons in its third shell, which is its outer shell. As a result, it forms _______ covalent bonds with other atoms.

Explain what a polar molecule is

Which of the following elements is least abundant in your body

Which of the following are compounds

At atom can be changed into an ion by adding or removing____________. an atom can be changed into a different isotope by adding or removing___________. But if you change the number of __________, the atom becomes a different element.

At atom can be changed into an ion by adding or removing______. an atom can be changed into a different isotope by adding or removing_. But if you change the number of ______, the atom becomes a different element.