Chemistry Unit 1

Question 1

What is the Precision rule in significant digits?

Answer 1

When adding/subtracting, the answer must have the same decimal placement as the given value with the least.

Question 2

What is the Certainty rule in significant digits?

Answer 2

When multiplying/dividing, the answer must have the same number of significant digits as the given with the least.

Question 3

Define Accuracy in the context of measurements.

Answer 3

How close the measurements are to the true/correct/accepted value.

Question 4

Define Precision in the context of measurements.

Answer 4

How close together the measurements are to each other even when they are far from the true/correct/accepted value.

Question 5

Why are accuracy and precision important in scientific analysis?

Answer 5

Accuracy prevents mishaps and precision shows a reliable method used.

Question 6

Who determined the charge to mass ratio of an electron?

Answer 6

J.J. Thomson (1903).

Question 7

What did Robert Milikan find about the mass of an electron?

Answer 7

The mass of the electron is 9.11x10-31 kg.

Question 8

What are Groups/Families in the Periodic Table?

Answer 8

Vertical columns on the table that share similar chemical properties.

Question 9

What do main groups in the Periodic Table indicate?

Answer 9

They indicate valence electrons.

Question 10

What are Periods in the Periodic Table?

Answer 10

Horizontal rows on the table that indicate the number of energy levels an atom has.

Question 11

What are the physical properties of metals?

Answer 11

Good conductors, solids at room temperature (except Hg), lustrous, ductile, malleable, and high melting points.

Question 12

What are the properties of non-metals?

Answer 12

Poor conductors, brittle, can be solid, liquid, or gas at room temperature.

Question 13

What are metalloids?

Answer 13

Elements that have properties between metals and non-metals, such as being shiny or dull and often semi-conductors.

Question 14

Define Isotopes.

Answer 14

Atoms with the same number of protons but different numbers of neutrons.

Question 15

How are isotopes identified?

Answer 15

By atomic number (Z) and mass number (A).

Question 16

What is the equation for calculating average atomic mass?

Answer 16

Average Atomic Mass = ∑(element mass)(relative abundance).

Question 17

What is the trend of Atomic Radius across the Periodic Table?

Answer 17

Decreases from left to right and increases down a group.

Question 18

What is Ionization Energy?

Answer 18

The energy needed to remove a valence electron from an atom or ion in its gaseous state.

Question 19

What is the trend of Ionization Energy across the Periodic Table?

Answer 19

Increases from left to right and decreases down a group.

Question 20

Define Electron Affinity.

Answer 20

Energy released when a gaseous atom gains an electron.

Question 21

What is the trend of Electron Affinity across the Periodic Table?

Answer 21

Increases up a group and from left to right in a period.

Question 22

What is Electronegativity?

Answer 22

The attraction an atom has to the electrons it is covalently sharing.

Question 23

What is the trend of Electronegativity across the Periodic Table?

Answer 23

Increases from down to up a group and from left to right in a period.

Question 24

What is an Ionic Bond?

Answer 24

A force of attraction between oppositely charged ions due to the transfer of electrons.

Question 25

What are Cations?

Answer 25

Ions with a positive charge; they lose electrons.

Question 26

What are Anions?

Answer 26

Ions with a negative charge; they gain electrons.

Question 27

List properties of ionic compounds.

Answer 27

* Hard * Brittle * Solid at room temperature * Crystal lattice structure.

Question 28

What are Electrolytes?

Answer 28

Ionic compounds that can conduct electricity when dissolved in water.

Question 29

What is a Covalent Compound?

Answer 29

Forms through the sharing of electrons to complete the octet rule.

Question 30

What are properties of covalent compounds?

Answer 30

* All states at room temperature * Low melting and boiling points * Produce non-conducting solutions.

Question 31

What is a Co-ordinate covalent bond?

Answer 31

One atom contributes both electrons.

Question 32

What is an Incomplete Octet?

Answer 32

A central atom has less than 8 electrons around them.

Question 33

What is the VSEPR theory?

Answer 33

Valence-Shell Electron-Pair Repulsion theory used to determine molecular shape.

Question 34

What is Polarity in molecules?

Answer 34

The distribution of electrical charge in a molecule.

Question 35

What is the difference between Intermolecular and Intramolecular forces?

Answer 35

* Intermolecular: Forces between two molecules * Intramolecular: Forces within the molecule.

Question 36

List the types of intermolecular forces from strongest to weakest.

Answer 36

* Ion-induced dipole or ion-dipole * Hydrogen Bonding * Dipole-Dipole * London Dispersion Forces.

Question 37

What is the Law of Conservation Mass?

Answer 37

Mass is neither created, nor destroyed in a chemical reaction ## Footnote This law is fundamental in chemistry and states that the total mass of reactants equals the total mass of products.

Question 38

What does the Law of Definite Proportion?

Answer 38

Different samples of the same compound always contain its constituents’ elements in the same proportions by mass ## Footnote This principle ensures that a chemical compound has a consistent composition regardless of its source.

Question 39

Fill in the blank: The Law of Multiple Proportions (Dalton) states that when two elements can make more than one compound combined, the masses of one element that combined with a fixed mass of the other element are in ratio of _______.

Answer 39

small whole numbers ## Footnote This law highlights the different ways elements can combine to form various compounds.

Question 40

What is the common name for the element with the symbol Sb?

Answer 40

antimony ## Footnote The Latin name for antimony is stibnum.

Question 41

What is the common name for the element with the symbol Cu?

Answer 41

copper ## Footnote The Latin name for copper is cuprum.

Question 42

What is the common name for the element with the symbol Au?

Answer 42

gold ## Footnote The Latin name for gold is aurum.

Question 43

What is the common name for the element with the symbol Pb?

Answer 43

lead ## Footnote The Latin name for lead is plumbum.

Question 44

What is the common name for the element with the symbol Fe?

Answer 44

iron ## Footnote The Latin name for iron is ferrum.

Question 45

What is the common name for the element with the symbol Sn?

Answer 45

tin ## Footnote The Latin name for tin is stannum.

Question 46

What is the lower charge for antimony in the classical naming system?

Answer 46

stibnous ## Footnote This refers to antimony in a +3 oxidation state.

Question 47

What is the higher charge for antimony in the classical naming system?

Answer 47

stibnic ## Footnote This refers to antimony in a +5 oxidation state.

Question 48

What is the lower charge for copper in the classical naming system?

Answer 48

cuprous ## Footnote This refers to copper in a +1 oxidation state.

Question 49

What is the higher charge for copper in the classical naming system?

Answer 49

cupric ## Footnote This refers to copper in a +2 oxidation state.

Question 50

What is the lower charge for gold in the classical naming system?

Answer 50

aurous ## Footnote This refers to gold in a +1 oxidation state.

Question 51

What is the higher charge for gold in the classical naming system?

Answer 51

auric ## Footnote This refers to gold in a +3 oxidation state.

Question 52

What is the lower charge for lead in the classical naming system?

Answer 52

plumbous ## Footnote This refers to lead in a +2 oxidation state.

Question 53

What is the higher charge for lead in the classical naming system?

Answer 53

plumbic ## Footnote This refers to lead in a +4 oxidation state.

Question 54

What is the lower charge for iron in the classical naming system?

Answer 54

ferrous ## Footnote This refers to iron in a +2 oxidation state.

Question 55

What is the higher charge for iron in the classical naming system?

Answer 55

ferric ## Footnote This refers to iron in a +3 oxidation state.

Question 56

What is the lower charge for tin in the classical naming system?

Answer 56

stannous ## Footnote This refers to tin in a +2 oxidation state.

Question 57

What is the higher charge for tin in the classical naming system?

Answer 57

stannic ## Footnote This refers to tin in a +4 oxidation state.