Chapter 2 - Nature of Molecules; Props of H20

Question 0

Atomic number

Answer 0

of protons in nucleus- determines chemical

Question 1

Atomic Mass

Answer 1

of protons and neutrons

Question 2

Mass

Answer 2

Amount of a substance

Question 3

Element

Answer 3

Any substance that cannot be broken down to any other substance by ordinary chemical means

Question 4

Dalton

Answer 4

Mass of atoms and subatomic particles is measured in daltons

Question 5

Neutral atom

Answer 5

Have same numbers of protons and electrons

Question 6

Ion

Answer 6

Charged particle that is formed when an atom gains or loses an electron

Question 7

Cation

Answer 7

Atom having more protons than electrons; has a net positive charge

Question 8

Anion

Answer 8

Atom with fewer protons than electrons; carries negative net charge

Question 9

Isotope

Answer 9

Atoms of a single element that possess different #s of neutrons

Question 10

Oxidation

Answer 10

Loss of electron by atom or molecule; in metabolism, often associated with a gain of oxygen or loss of hydrogen.

Question 11

Reduction

Answer 11

Electron(s) passed from one atom to another

Question 12

Redox reaction

Answer 12

One species is reduced another oxidized

Question 13

Valence electron

Answer 13

Can participate in the formation of a chemical bond

Question 14

Octet rule

Answer 14

The octet rule is a chemical rule of thumb that states that atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas.

Question 15

Organic compound

Answer 15

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon.

Question 16

Molecule

Answer 16

A molecule /ˈmɒlɪkjuːl/ is an electrically neutral group of two or more atoms held together by chemical bonds.

Question 17

Chemical compound

Answer 17

a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions.

Question 18

Ionic bond

Answer 18

a type of chemical bond that involves the electrostatic attraction between oppositely charged ions. These ions represent atoms that have lost one or more electrons (known as cations) and atoms that have gained one or more electrons (known as an anion). In simpler words, an ionic bond is the transfer of electrons from a metal to a non-metal in order for both atoms to obtain a full valence shell.

Question 19

Chemical bond

Answer 19

attraction between atoms that allows the formation of chemical substances that contain two or more atoms. The bond is caused by the electrostatic force of attraction between opposite charges between electrons and nuclei

Question 20

Covalent bond

Answer 20

A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding.

Question 21

Hydrogen bond

Answer 21

A hydrogen bond is the attractive force between the hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule. Usually the electronegative atom is oxygen, nitrogen, or fluorine, which has a partial negative charge.

Question 22

Van der waals attraction

Answer 22

A weak attractive force between atoms or nonpolar molecules caused by a temporary change in dipole moment arising from a brief shift of orbital electrons to one side of one atom or molecule, creating a similar shift in adjacent atoms or molecules.

Question 23

Ionic compound

Answer 23

chemical compound in which ions are held together by ionic bonds.

Question 24

Single covalent bond

Answer 24

A single bond is when two electrons–one pair of electrons–are shared between two atoms. It is depicted by a single line between the two atoms. Although this form of bond is weaker and has a smaller density than a double bond and a triple bond, it is the most stable because it has a lower level of reactivity meaning less vulnerability in losing electrons to atoms that want to steal electrons.

Question 25

Double covalent bond

Answer 25

A Double bond is when two atoms share two pairs of electrons with each other. It is depicted by two horizontal lines between two atoms in a molecule. This type of bond is much stronger than a single bond, but less stable; this is due to its greater amount of reactivity compared to a single bond.

Question 26

Structural formula

Answer 26

Eg: h-h, o=o

Question 27

Molecular formula

Answer 27

H2, O2

Question 28

electronegativity

Answer 28

Affinity for electrons. Force atoms used to try to pull electron from another atom (attracted negatives and positives). They “share” by this “tug of war.”

Question 29

Nonpolar covalent bond

Answer 29

Electrons (+/-) equally shared, resulting in non-polar molecules

Question 30

Polar covalent bond

Answer 30

Electrons are unequally shared and sharing is so unequal it results in polar molecules (more of a charge in one part than another)

Question 31

Nonpolar molecule

Answer 31

A molecule may be nonpolar either when there is an equal sharing of electrons between the two atoms of a diatomic molecule or because of the symmetrical arrangement of polar bonds in a more complex molecule.

Question 32

Polar molecule

Answer 32

A polar molecule has a net dipole as a result of the opposing charges (i.e. having partial positive and partial negative charges) from polar bonds arranged asymmetrically. Water (H2O) is an example of a polar molecule since it has a slight positive charge on one side and a slight negative charge on the other.

Question 33

Chemical reaction

Answer 33

Formation and breaking of chemical bonds. All involve shifting of atoms from one molecule or ionic compound or another, without change in # or identity of atoms

Question 34

Reactants & products

Answer 34

A+B -> C+D

Question 35

Catalyst

Answer 35

Substance that increases rate of reaction

Question 36

Cohesion

Answer 36

Molecules sticking together

Question 37

Adhesion

Answer 37

H20 molecules tend to stick to charged surfaces

Question 38

Surface tension

Answer 38

Result of cohesion

Question 39

Buffer

Answer 39

Substance that resists changes in pH. Act by releasing H+s when a base is added and absorbing H+s when acid is added, with effect of keeping H+ relatively constant

Question 40

Base

Answer 40

Combines with H+ when dissolved in H20, and thus lowers H+. Raises pH. pH value above 7.

Question 41

Acid

Answer 41

Dissociates in H20 to increase H+ (decreasing pH).

Question 42

pH scale

Answer 42

Used to measure relative strength of acidic and basic solutions

Question 43

Hydration shell

Answer 43

Sucrose molecule dissociates, or breaks away, from a solid sugar crystal, H20 molecules surround it in a cloud, forming H she’ll that prevents it from associating with sucrose molecules

Question 44

Hydrophobic exclusion

Answer 44

Tendency of Nonpolar molecules to aggregate in H20

Question 45

Mole

Answer 45

Defined as weight of substance in grams that corresponds to atomic masses of all of the atoms in a molecule of that substance

Question 46

Hydrogen ion

Answer 46

hydrogen ion, strictly, the nucleus of a hydrogen atom separated from its accompanying electron. The hydrogen nucleus is made up of a particle carrying a unit positive electric charge, called a proton. The isolated hydrogen ion, represented by the symbol H +, is therefore customarily used to represent a proton.

Question 47

Hydroxide ion

Answer 47

The hydroxide ion is a negatively charged molecule made up of one oxygen bonded to one hydrogen. When dissolved in water, the hydroxide ion is an incredibly strong base. In fact, according to the Arrhenius definition of a base, the presence of a hydroxide ion is what makes a chemical a base.

Question 48

Hydrocarbon

Answer 48

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls.

Question 49

Functional group

Answer 49

In organic chemistry, functional groups are specific groups of atoms or bonds within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction(s) regardless of the size of the molecule it is a part of.

Question 50

Hydroxyl group

Answer 50

The hydroxyl group is a pair of atoms that is commonly found in organic compounds such as sugars and alcohols. Learn more about the importance of this group and quiz yourself at the end.

Question 51

Carbonyl group

Answer 51

In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a carbonyl group is often referred to as a carbonyl compound.