unit 4

Question 1

Alkali metal

Answer 1

An element in Group 1 of the periodic table. These elements are extremely reactive and will react spontaneously with water creating hydrogen gas and hydroxide ions in solution.

Question 2

Alkaline Earth Metal

Answer 2

An element in Group 2 of the periodic table. These elements are reactive (but less so than Group 1), creating hydrogen gas and hydroxide ions in solution.

Question 3

Anion

Answer 3

A negatively charged ion

Question 4

Atomic radius

Answer 4

Half the distance between adjacent nuclei. Size of an atom in Picometers (pm)

Question 5

Brittle

Answer 5

The ability to be crushed into pieces when hammered, a property of nonmetals.

Question 6

Cation

Answer 6

A positively charged ion.

Question 7

Diatomic Molecule

Answer 7

A nonmetal atom that forms one or more nonpolar covalent bonds with another atom of the same element to form a molecule consisting of the two atoms when there is no other element to bond with. Elements that do this are Br, I, N, Cl, H, O and F. BRINClHOF like brinklehoff

Question 8

Ductile

Answer 8

The ability to be stretched into a wire, a property of metals.

Question 9

Dull

Answer 9

The lack of ability to reflect light efficiently, a property of nonmetals.

Question 10

Group

Answer 10

Columns down the periodic table that contain elements with the same number of valence electrons and thus similar chemical properties. Aka “families”

Question 11

Electronegativity

Answer 11

The relative ability for an atom to gain an electron. Fluorine has the highest electronegativity 4.0. INCREASES across a period and DECREASES down a group

Question 12

Effective nuclear charge

Answer 12

The overall attraction to the nucleus that a valence electron experiences. This increases as the # of protons increases and the occupied number of energy levels remains the same

Question 13

Halogen

Answer 13

An element in Group 17 of the periodic table. These elements are extremely reactive, not as much as groups 1 and 2. e.g. fluorine, chloride, bromine, etc

Question 14

Ionization energy

Answer 14

The energy required to remove an electron from the valence shell. Unit: kJ/mol Kilojoules per mol. It INCREASES across a period and DECREASES down a group.

Question 15

Ionic radius

Answer 15

The size of an ion compared to the original atom. Metal atoms lose electrons and form + charged ions that are SMALLER than the original atom, nonmetal atoms form – charged ions that are LARGER than the original atom.

Question 16

Luster

Answer 16

The ability to reflect light, a property of metals.

Question 17

Malleable

Answer 17

The ability to be hammered or rolled into thin sheets, a property of metals.

Question 18

Metal

Answer 18

Elements that have low electronegativity and ionization energy and large radius that tend to lose electrons to form chemical bonds. Most of the periodic table is metals

Question 19

Metallic Character

Answer 19

describes the set of chemical properties that are usually associated with the elements classified as metals in the periodic table ie. LOSING ELECTRONS conductor, malleable, ductile. increases <- and v

Question 20

Metalloid

Answer 20

Elements that exhibit properties of both metals and nonmetals. B, Si, Ge, As, Sb, Te (sometimes Po and As)

Question 21

Orbital

Answer 21

The location in the electron cloud with the highest probability of finding an electron.

Question 22

Monatomic atom

Answer 22

A molecule composed of just one atom

Question 23

Noble gases

Answer 23

A Group 18 element on the periodic table. These elements are nonreactive, with a full valence shell (8).

Question 24

Nonmetal

Answer 24

Elements that have high electronegativity and ionization energy and small radius that tend to gain or share electrons to form chemical bonds.

Question 25

Properties of metals

Answer 25

good conductors of heat and electricity, dense, malleable, ductile, lose electrons easily, high melting points, lustrous, solid at room temp (EXCEPT MERCURY)

Question 26

Properties of non metals

Answer 26

bad conductors of heat and electricity, low density, brittle, gains electrons easily, low melting points, dull.

Question 27

Properties of metalloids

Answer 27

variable conductors of heat and electricity, variable density, brittle, gains or loses electrons, variable melting points, and lustrous.

Question 28

Nonreactive

Answer 28

Not capable of readily gaining or losing e’s or undergoing a chemical change/reaction. INERT. e.g. noble gases

Question 29

Oxidation

Answer 29

The loss of valence electrons from an atom or ion, resulting in the increase in oxidation number of an element.

Question 30

Periodic law

Answer 30

Properties of elements repeat in a predictable way when arranged by atomic number

Question 31

Periods

Answer 31

Rows across the periodic table with elements having the same number of occupied principal energy levels.

Question 32

Rare Earths/Inner Transition metals

Answer 32

F Block elements. Fill the F orbitals. Many are radioactive.

Question 33

Reactivity

Answer 33

aka “activity” is a measure of how readily a substance undergoes a chemical reaction.

Question 34

Reduction

Answer 34

The gain of valence electrons from an atom or ion, resulting in the decrease in oxidation number of an element.

Question 35

shielding effect

Answer 35

a decrease in attraction between electrons and the nucleus in an atom due to distance and repulsion between extra electrons and energy levels between the nucleus and valence electrons. More internal or “core electrons” lesson the effect of the nucleus on valence electrons

Question 36

shielding electrons

Answer 36

non-valence electrons, AKA core electrons

Question 37

transition metals

Answer 37

Metals from D Block. Display classic metallic properties. Hard, shiny, ductile, malleable and they make COLORED IONS in solution and colored crystals as a solid. They also have multiple oxidation numbers (polyvalent)

Question 38

Z effective

Answer 38

The net attraction from the positive nucleus that a negative valence electron can “feel”. The core electrons are said to shield the valence electrons from the full attractive forces of the protons in the nucleus. Zeff = Z -S Z is nuclear charge, S is the number of core electrons. The higher the Zeff, the greater the relative attraction for valence electrons

Question 39

Antoine Lavoisier

Answer 39

"Father of modern chemistry" who first organized the 'elements' (some were compounds, not elements). His 'list of simple substances' was ordered based off of reactivity w/ oxygen and other elements

Question 40

Johann Dobereiner

Answer 40

scientist who made Model of Triads in 1829. He grouped 3 sets of 3 elements with similar chemical properties (e.g. Li, Na, and K reacting with water, chlorine and hydrogen similarly).

Question 41

Law of triads

Answer 41

Law connected to Johann Dobereiner which states the atomic mass of the middle element in a triad about equals the mean of the 1st and 3rd atomic masses. (1st observed pattern in the elements)

Question 42

John Newlands

Answer 42

Scientist who created the law of octaves in 1865.

Question 43

Law of Octaves

Answer 43

law created by John Newlands. When elements placed in order of atomic weights, every 8th element has similar properties to the 1st. (predecessor of periodic law)

Question 44

Dmitri Mendeleev

Answer 44

OUR MAN who created 1st periodic table in 1869. He arranged them in a grid and listed elements in atomic mass. He predicted the existence and properties of elements not yet discovered e.g. Gallium

Question 45

Henry Moseley

Answer 45

Made the modern periodic table! He ordered the elements in increasing atomic number.

Question 46

Moseley's experiments

Answer 46

Lowkey don't understand this ahaha Moseley shot beta particles at atoms and on impact, each element emitted an X ray with a unique frequency. He made graph by plotting the sq root of the x ray frequency vs the atomic number, and found that it was an increasing linear graph. This means that the atomic number was equal to the amount of charge in the nucleus, and the atomic number = the number of protons

Question 47

Periodicity

Answer 47

tendency to recur at intervals

Question 48

How to know valence electrons based on spdf notation

Answer 48

total number of s and p in the highest PEL

Question 49

Alloy

Answer 49

mixture or blend of 2 or more metallic elements. Made from melting then mixing metals, properties differ to original metals.

Question 50

representative elements

Answer 50

elements group 1,2,13-18 that make up the 'main group' of elements with regular properties i think