Chapter 2 HW

Describe energy

It does not have mass or occupy space

Do covalent bonds share one or more pairs of electrons?

Yes

Carbon atoms have 4 valence electrons. Are they likely to react with other atoms, and why or why not?

Yes, because they can become more stable by doing so

Covalent bonds

Involve the sharing of one to three pairs of electrons

What type of bond is formed when electrons are transferred from one atom to another?

Ionic bond

Atoms that have lost or gained electrons are known as __________.

Ions

How do ions form ionic bonds?

Ions of opposite electrical charges are attracted to each other to balance the charges

A solution with a pH of 7 is _________________.

Neutral

Which subatomic particles contribute to an atom's mass number but not its atomic number?

Neutrons

Isotopes have different numbers of _______________; thus they have also have different _______________.

Neutrons Atomic masses

Atoms of oxygen have a total of 8 electrons. Are these atoms stable, and why or why not?

No, because the atoms have only 6 valence electrons, but need 8 for stability

What distinguishes hydrogen bonds from covalent bonds?

Only hydrogen bonds can form between molecules

How are polar covalent bonds shared?

The electrons are shared unequally

An atom's outermost shell is known as its _________________ shell.

Valence

Which parts of atoms can interact (react) to form chemical bonds?

Valence electrons

Calcium's atomic number is 20. It forms ions with 18 electrons, what is the electrical charge of a calcium ion?

+2

What is the number of neutrons in an atom with atomic mass of 35, 3 energy levels, and 7 valence electrons?

18

How many electrons can shell 1 of an atom hold?

2

Polar molecules, like water, result when electrons are shared ______________.

unequally between atoms

An atom of oxygen has an atomic number of 8 and a mass number of 18. How many of each type of subatomic particle does it contain?

8 protons, 8 electrons, and 10 neutrons

Define compound

A molecule composed of two or more elements

An atomic symbol is _________________.

A one or two letter abbreviation for an element

What are nucleotides composed of?

A phosphate group, a five-carbon sugar, and a nitrogen-containing base

What are the complementary base pairs of DNA?

Adenine and Thymine Guanine and Cytosine

Proteins are synthesized from ___________________ during synthesis reactions.

Amino acids

What is an ion?

An atom that has either gained or lost electron(s)

Elements are composed of building blocks known as _______________.

Atoms

What are enzymes?

Biological catalysts

Rank the types of chemical bonds, in order, from strongest to weakest

Covalent, Ionic, Hydrogen

What type of chemical reaction is used by liver cells when synthesizing glycogen from glucose?

Dehydration synthesis

Describe the structure of a nucleotide found in DNA

Deoxyribose sugar, nitrogen-containing base, phosphate group

Unsaturated fatty acid chains contain one or more __________________ bonds between carbon atoms.

Double

Nerve impulses involve the flow of an electrical current, a type of energy known as ____________________ energy.

Electrical

The subatomic particles that are responsible for the chemical behavior of atoms are the ________________.

Electrons

What determines the chemical behavior of an atom?

Electrons in the valence shell

Give a statement reflecting the relationship between elements, atoms, and chemical symbols.

Elements are composed of atoms

At the beginning of glycolysis, ATP transfers a phosphate group to glucose. What type of chemical reaction is this?

Exchange reaction

Calcium

Found in bones and teeth, and it is required for blood clotting

Which carbohydrate is also known as blood sugar?

Glucose

What does formation of hydrogen bonds require?

Hydrogen atoms and polar covalent bonds

What is the main type of lipid found in cellular membranes?

Phospholipids

A molecule of water (H2O) is formed by what type of bond?

Polar covalent bonds

In which category of organic molecules would you place compounds that catalyze chemical reactions?

Proteins

An acid is a molecule that releases (donates) __________________.

Protons (hydrogen ions)

Which type(s) of subatomic particles can be located within the nucleus of an atom?

Protons and neutrons

Give an example of kinetic energy

Skeletal muscles contracting as a person lifts weights

Which ions are essential for nerve impulses?

Sodium and potassium

Sodium

The major extracellular cation

Potassium

The major intracellular cation

Chlorine

The most abundant extracellular anion

When an ionic bond forms, which part(s) of the atoms are directly involved?

The outermost electrons

The building blocks of a triglyceride are _____________________.

Three fatty acid chains and one glycerol molecule

Iron

Transports oxygen inside RBCs

Define molecule

Two or more atoms combined chemically