Exam Review

Question 1

What is matter?

Answer 1

It’s anything that has mass and takes up space.

Question 2

What is an atom?

Answer 2

It’s the smallest unit of matter that has the properties of an element.

Question 3

What is a compound?

Answer 3

A substance formed when two or more chemical elements are chemically bonded together.

Question 4

What is a chemical property?

Answer 4

A change of a material’s properties that happen during or after a chemical reaction (basically any quality that can be seen only by changing a substance’s chemical identity)

Question 5

What is a physical property?

Answer 5

Physical properties can be observed or measured without changing the composition of matter.

Question 6

What is a physical change?

Answer 6

It is changes affecting the form of a chemical substance, but not its chemical composition.

Question 7

What is an electron?

Answer 7

The smallest of the particles that make up an atom and they have a negative charge -1

Question 8

What is a proton?

Answer 8

It’s a subatomic particle found in an atom and has a positive charge +1 (opposite of an electron)

Question 9

What is a neutron?

Answer 9

It’s a subatomic particle found in the nucleus of atoms and is neutral (zero charge)

Question 10

What is a molecule?

Answer 10

The smallest particle in a chemical element or compound that has the chemical properties.

Question 11

What is a mixture?

Answer 11

A material made up of two or more different substances which are mixed but are not combined chemically.

Question 12

What is ionization energy?

Answer 12

The amount of energy required to remove the most loosely bound electron (the valence electron) to form a cation.

Question 13

What is a solution?

Answer 13

A homogeneous mixture composed of two or more substances

Question 14

What is a concentration?

Answer 14

The number of molecules or ions in a given volume of a substance, expressed as mol/L (molarity).

Question 15

What is a solute?

Answer 15

A substance dissolved in another substance, known as a solvent.

Question 16

What is a solvent?

Answer 16

A substance that dissolves a solute resulting in a solution

Question 17

What is a homogeneous mixture?

Answer 17

A mixture which has uniform composition and properties throughout. ie. oooooooo

Question 18

What is a heterogeneous mixture?

Answer 18

A mixture in which the components can be seen ie. oooo0o0oo

Question 19

What is a qualitative chemical analysis?

Answer 19

The identification of elements or grouping of elements present in a sample

Question 20

What is a quantitative chemical analysis?

Answer 20

the determination of the absolute or relative abundance (usually expressed as a concentration) of one, a bunch or all substance(s) in a sample.

Question 21

What is isoelectronic?

Answer 21

Refers to two atoms, ions or molecules that have the same electronic structure and same number of valence electrons.

Question 22

What is the activity series?

Answer 22

A chart of metals listed in order of declining relative reactivity. The top metals are more reactive than the metals on the bottom.

Question 23

What is the Law of Conservation of Mass?

Answer 23

This law states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. Mass of product in chemical reaction = mass of reactants.

Question 24

What is the Law of Definite Proportions?

Answer 24

(Proust’s law) States that a chemical compound always contains its component elements in fixed ratio (by mass)

Question 25

What is the Law of Constant Composition?

Answer 25

States that all samples of a chemical compound have the same elemental composition by mass

Question 26

What is an atomic mass unit?

Answer 26

Unit of mass used to express atomic and molecular weights.

Question 27

What is atomic mass?

Answer 27

Mass of an atom of a chemical element. The mass number is the total number of protons and neutrons combined

Question 28

What is the molecular mass?

Answer 28

The mass of a molecule.

Question 29

What is molar mass?

Answer 29

For ie. mmH2O=18.01 (16+2(1.01). It's just the masses added up.

Question 30

What is an ion?

Answer 30

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

Question 31

What is a cation?

Answer 31

A positively charged ion

Question 32

What is an anion?

Answer 32

A negatively charged ion

Question 33

What is an isotope?

Answer 33

The number of protons in an atom's nucleus. For example, an atom with 6 protons must be carbon

Question 34

What is electron affinity?

Answer 34

The amount of energy released or spent when an electron is added to a neutral atom or molecule

Question 35

What is a pure substance?

Answer 35

Homogeneous substance that has consistent properties throughout the sample.

Question 36

What is electronegativity?

Answer 36

Tendency of an atom to attract a bonding pair of electrons.

Question 37

What are valance electrons?

Answer 37

The outside electrons are the most easily lost.

Question 38

What is an ionic bond?

Answer 38

The complete transfer of valence electron(s) between a metal and non-metal

Question 39

What is a covalent bond?

Answer 39

The sharing of electron pairs between two non metals.

Question 40

What is a non polar covalent bond?

Answer 40

A type of chemical bond where two atoms share a pair of electrons with each other.

Question 41

What is a polar covalent bond?

Answer 41

A type of chemical bond where a pair of electrons is unequally shared between two atoms.

Question 42

What is effective nuclear charge?

Answer 42

The net positive charge experienced by an electron in a multi-electron atom.

Question 43

What is the periodic law?

Answer 43

Properties of the elements are periodic functions of their atomic numbers. Also called Mendeleev's law.

Question 44

What is a period? A group?

Answer 44

Period is across the table. Group is down the table (which is a chemical family).

Question 45

Group names on the periodic.

Answer 45

1. Alkali metals 2. Alkali earth metals 3-12. Transition metals 13-16. No approved names 17. Halogens 18. Nobel gases

Question 46

Contribution each scientist made on the structure of the atom: Dalton, Thompson, Rutherford and Bohr.

Answer 46

Dalton- Proposed that all matter is composed of very small things which he called atoms. Thompson- Proposed the plum pudding model of the atom that had no nucleus and is composed of + and - charged particles. Rutherford- An atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths. Bohr- Depicted the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus

Question 47

Periodic trends: Increase or decrease? - atomic radius - 1st ionization energy - electronegativity

Answer 47

Atomic radius Across period= decrease Down a group= increase 1st ionization energy Across period= increase Down a group= decrease Electronegativity Across period= increase Down a group= decrease

Question 48

What group of elements has the lowest electron affinity? Why?

Answer 48

Metals. Because metals lose electrons to become balanced rather than gain