BIOL 1100 - CH. 2

the attraction of water to other polar substances is called

adhesion

molecules that are more polar tend to have which of the following characteristics?

higher heat of vaporization, higher specific heat

what is the temperature of a substance a measure of?

how fast its molecules are moving

The amino acid glycine (C3NO2H6) is a(an):

organic molecule

subatomic particles called _____ can be found at various distances from the nucleus

electrons

in the crystal matrix of ordinary salt, the sodium and chlorine are held together by:

ionic bonds

an atom is composed of a central nucleus which is surrounded by which orbiting particles?

electrons

negatively charged subatomic particles that have almost no mass are called:

electrons

redox reactions involve a transfer of ___ from one atom to another

electrons

the chemical behavior of an atom is determined by the number and configuration of its ____

electrons

the green spheres (indicated by arrows) in the simple "bohr model" of atoms shown here represent ____.

electrons

in living organisms, almost all chemical reactions are catalyzed by protein catalysts called

enzymes

in living systems, which of the following catalyze almost every chemical reaction necessary for life?

enzymes

when NaCl is formed, ___

a sodium atom loses an electron, while a chlorine atom gains an electron

the attraction of water to other polar substance is called

adhesion

if two atoms have the same number of protons in their nucleus, you can conclude for sure that they ____

are atoms of the same elements

in a neutral atom, the number of electrons is equal to which of the following?

atomic number

water is cohesive because water molecules are ___

attracted to each other

valence electrons and their interactions determine the ____ properties of an element

chemical

the number and configuration of electrons determines an elements _____

chemical properties

because polar water molecules attract each other, water is said to be ___

cohesive

water consists of one oxygen atom joined to two hydrogen atoms by two single, polar ____ bonds

covalent

water consists of one oxygen atom joined to two hydrogen atoms by what type of bonds?

covalent

when two atoms share a pair of electrons, this bonding is referred to as:

covalent

Oxygen-16 is abundant and has 8 protons and 8 neutrons. Oxygen-18 has two extra neutrons. These two forms are:

oxygen isotopes

if two atoms are joined by a polar covalent bond the atom with the lower electronegativity will have partial ______ charge.

positive

Among subatomic particles, a(n) _______ has a charge of +1, a(n) _________ has a charge of -1, and a(n) ________ has no charge

proton, electron, neutron

Atomic number refers to the number of ___ in an atom

protons

the atomic number of an element refers to the number of _____ in the atoms of that element.

protons

chemical reactions that involve a transfer of electrons from one atom to another are called ___ reactions

redox, reduction-oxidation or oxidation-reduction

the atoms in NaCl are held together by what type of bond?

ionic

life is thought to have evolved from complex molecules formed by the interaction of smaller molecules in the ocean and atmosphere. The substance which brought these molecules together to interact is:

water

when 1g of fructose is dissolved in 500 mL of water, ___ is the solvent and ____ is the solute

water, fructose or sugar

___ can be defined as any substance that has mass and occupies space.

matter

anything that has mass and occupies space is defined as:

matter

a group of atoms held together by chemical bonds in a stable association is called:

molecule

a(n) ___ is made of two or more atoms held together by chemical bonds in a stable association. the atoms may or not belong to the same element.

molecule

atomic nuclei contain protons and ____

neutrons

generally speaking, an atom is made of a central ___ which is sureounded by orbiting _____

nucleus, electrons

carbon has four balance electrons and oxygen has six. carbon dioxide would contain ___

one single covalent bond

A hydrogen ion, formed during the dissociation of water, has a charge of which of the following?

+1

arrange the following states of water in order from most dense to least dense - solid - liquid - gas

1. liquid 2. solid 3. gas

which of the following are subatomic particles? - Electrons - Ions - Orbitals - Neutrons - Protons

- Electrons -Neutrons - Protons

select all that apply molecules that are more polar tend to have which of the following characteristics? - a higher specific heat - a lower specific heat - a lower heat of vaporization - a higher heat of vaporization

- a higher specific heat - a higher heat of vaporization

which subatomic particles are located in the nucleus of an atom? - neutrons - ions - electrons - protons

- neutrons - protons

the three main types of subatomic particles are:

- protons - neutrons - electrons

what is the charge of a hydroxide ion?

-1 A hydroxide ion is formed when a water molecule loses a hydrogen ion.

____________ atoms always have one proton

Hydrogen

The common basilisk lizard will run across water on its hind legs in an erect position when startled by predators. This lizard has large feet and flaps of skin along its toes. What properties of water allow this lizard to walk on water?

The surface tension created by hydrogen bonds is greater than the weight of the lizard initially.

if two atoms are joined by a polar covalent bond, the shared electrons will tend to stay closer to the atom with ___

higher electronegativity

what is the temperature of a substance a measure of? - how many hydrogen bonds are formed between its molecules - the adhesive properties of its molecules - how fast it's molecules are moving

how fast its molecules are moving

____ atoms usually have no neutrons

hydrogen

water molecules are polar, with regions that exhibit partial positive or negative charges. These opposite charges allow water molecules to attract each other via:

hydrogen bonds

consider a large protein molecule that has some parts that are highly hydrophobic. When placed in a water solution, the protein folds in a globular shape, such that all the hydrophobic portions are inside the molecules, away from the water. This is an example of which of the following?

hydrophobic exclusion

which property of water strongly affects the overall shape of many biological molecules, such as protein, and DNA?

hydrophobic exclusion

proteins are three dimensional molecules made from strands of amino acid (imagine a string of beads). there are 20 different amino acids that can be used in proteins found in living organisms. some of these amino acids are polar and others are nonpolar. in the watery cytosol of the cell, the proteins folds into the three dimensional structure. where would a series of nonpolar amino acids most likely be located in a protein that is found in a cytosol of an animal cell?

in the interior of the protein

where are valence electrons of an atom found?

in the outermost energy level only

in a chemical analysis of a sample of animal tissue, which element would you expect to find in the least quantity?

iodine

when atoms gain or lose electrons, they can become negatively or positively charged. These charged atoms are known as:

ions

what does it mean when we say water is adhesive?

it is attracted to other polar molecules and ions

solid water is ___ dense than liquid water

less

solid water is ______ dense than liquid water

less

when 1g of sugar is dissolved in 500mL of water, the sugar is called __________ and the water is called the __________

solute and solvent

the ___ of a substance is a measure of how rapidly it's individual molecules are moving

temperature or heat

which of the following is the definition of the heat of vaporization of water? - the temperature to which water has to be heated in order to produce 1g of water vapors in 1 hour - the amount of energy needed to raise the temperature of water by 1 C - the amount of energy needed to change 1g of water from liquid to gas

the amount of energy needed to change 1 g of water from a liquid to a gas

water has several properties important to life: high specific heat, high heat vaporization, lower density in solid form (ice), ability to act as a solvent and to organize nonpolar molecules. what explains these properties of water?

the polar nature of water molecules

a neutral atom has no net electrical charge? why?

there are equal numbers of protons and electrons in the atom

if two atoms belong to the same element, which of the following must be true? - the must have the same number of electrons - they must have the same number of protons - the must have the same number of neutrons

they must have the same number of protons