Self-Quiz

Life on Earth Chapter 2 Atoms, Molecules, and Life
Self-Quiz

What is the purest form of matter that cannot be separated into different substances by chemical means?
1. compounds
2. molecules
3. hormones
4. elements
5. electrons
What phrase best describes chemical bonds?
1. physical bridges
2. energy links
3. electronic glue
4. electronic orbitals
5. All of these phrases are equally descriptive.
When an atom ionizes, what happens?
1. It shares one or more electrons with another atom.
2. It emits energy as it loses extra neutrons.
3. It completely gives up or takes up one or more electrons.
4. It shares a hydrogen atom with another atom.
5. none of the above
If electrons in water molecules were equally attracted to hydrogen nuclei and oxygen nuclei, water molecules would be
1. more polar
2. less polar
3. unchanged
4. triple bonded
5. unable to form
Where are hydrogen bonds important to life?
1. between water molecules
2. between hydrogen atoms
3. in ionic substances
4. all of the above
5. none of the above
What is the defining characteristic of an acid?
1. It donates hydrogen ions.
2. It accepts hydrogen ions.
3. It donates or accepts hydrogen ions depending on the pH.
4. It has an excess of hydroxide ions.
5. It has a pH greater than 7.
Substances that cannot be broken down or converted to another substance are termed a(n)
1. element
2. molecule
3. ion
4. compound
5. mixture
Which factor is the most important when considering the atom reactivity?
1. An atom is the smallest particle of an element.
2. A molecule is the smallest unit of a compound.
3. Atoms are held together by interactions between their outermost electrons' shells.
4. The number of protons in the nucleus affects the size of the atom.
5. Atoms with many neutrons may be radioactive.
All of the following statements about energy are true-except
1. Kinetic energy is the energy of movement.
2. Potential energy is "stored" energy.
3. Light energy can be converted into heat.
4. Energy is the capacity to do work.
5. Potential energy cannot be converted to kinetic energy.
Chemically stable and unreactive atoms must have which of the following occur?
1. Their outermost energy shell must be filled with electrons.
2. The number of electrons must equal the number of protons.
3. Sharing of electron pairs is necessary.
4. Ionization is required.
5. They must be inert.
Polar bonds have which feature?
1. Electrons are shared unequally between atoms.
2. More than one pair of electrons is shared.
3. Ions are formed.
4. An acid and a base are combined.
5. Atoms from two molecules are attracted to each other.
Which statement describes water molecules?
1. They are charged and polar.
2. They are charged and nonpolar.
3. They are uncharged and polar.
4. They are uncharged and nonpolar.
5. They are ionically bonded.
How can an electron move from a low energy level to a high energy level?
1. It must release energy.
2. It must be shared between two atoms.
3. It must be radioactive.
4. It must absorb energy.
5. It cannot move to a higher energy level.
Organic molecules always contain which of the following:
1. carbon dioxide
2. carbon monoxide
3. carbon and nitrogen
4. carbon and hydrogen
5. carbon and oxygen
A neutral solution, pH 7
1. has no H+
2. has no OH-
3. has equal amounts of H+ and OH-
4. is hydrophobic
5. has a pH of 0
Which property (or properties) of water allows it to be perfectly structured to be a medium for living organisms?
1. high specific heat
2. high heat of vaporization
3. high heat of fusion
4. a and b
5. a, b, and c

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