UNIT 1: Properties and Structure of Matter | Unit Test

Atomic mass

Weight of nucleus

Atomic number

Number of protons in Atom

How to find number of neutrons

Atomic weight - atomic number

How to find number of electrons

Equal to number of protons when in base form

Define an Isotope

A species of an element that has the same number of protons but a different number of neutrons

Isotope Notation

Element-#Mass\

Value of A in Atomic Notation

Atomic Mass

Value of Z in Atomic Notation

Number of Protons

Value of X in Atomic Notation

Atomic Symbol

Abundance of Matter in Universe

80% hydrogen, 20% helium. These two elements were produced by the big bang.

How other elements were made

Through fusion and fission

Antoine Lavoisier’s contribution

• Published a list of the first known 33 elements in 1789

• Created the fist nomenclature for naming elements and compounds

Johann Wolfgang Döbereiner

• Organized elements into triads based on their properties (now known as groups)

  • Li-Na-K

  • Ca-Sr-Ba

  • Cl-Br-I

John Newlands

• Organized elements by their mass

• Noted that elements with similar properties occurred every 8 elements

  • Called this pattern “The Law of Octaves” (Periodicity/Periodic Law)

Dmitri Mendeleev

• Father of the periodic table

• Assembled the periodic table by atomic mass

• Elements with similar properties in columns

  • Left spaces for undiscovered elements

Henry Mosely

• Arranged elements by atomic number (number of protons)

Periodic Law

When elements are arranged into a list by atomic number, so properties of each element reoccur in a pattern

Group 1 Name

Alkali Metals

Group 1 Properties

Physical:

• Soft and Solid at room temperature

• Malleable

• Ductile

• Good conductors of heat & energy

Chemical:

• Form soluble basses (alkali solutions) in water

• Form oxides with formula X₂O

Group 2 Name

Alkaline Earth Metals

Group 2 Properties

Physical:

• Solid at room temperature

• Metallic character

  • Malleabe

  • Ductile

  • Good conductors

Chemical:

• Form insoluble basses in water

• Form oxides with formula XO

Group 17 Name

Halogens

Group 17 Properties

Physical:

• Solid/Liquid/Gas at room temperature

  • Low boiling point

• Non-metallic

Chemical:

• Reacts with metals to form solid salts MX, MX₂

• Forms diatomic molecules X₂

Group 18 Name

Noble Gasses

Group 18 Properties

Physical

• Gases at room temperature

• Non-metallic

Chemical:

• Very unreactive

  • Stable monatomic atoms

Trends of the Periodic Table

• Regular patterns that can be observed in the Periodic Table (Periodic Law)

• E.G. Atomic number and mass both increase going across periods and going down groups

Group 3 - 12 name

Transition elements

Elements B, Si, Ge, As, Sb and Te name

Transition metals

Atomic Number definition

Number of protons in an atom

Atomic mass defininition

Number of protons + neutrons

Atomic Number/Atomic Mass Group trend:

Increase

Atomic Number/Atomic Mass Period trend:

Increase

Define Number of valence electrons

The number of electrons in the outermost orbit of an atom

Number of valence electron group trend

Stays the same

Number of valence electrons period trend

Increases

Define atomic radius

The distance from the center of the atom to the outermost electrons. Indi

Atomic Radius Group Trend

Increases - Shielding from inner e^- increases

Atomic Radius Period Trend

Decreases - Nuclear charge increases

Define first ionization energy

The minimum amount of energy needed to remove the outermost electron from an isolated atom of a gaseous sample of an element

First Ionization Energy Group Trend

Decrease - shielding from inner e^- increases

First ionization energy period trend

Increase - Nuclear Charge increases

Define metallic character

Metals have characteristically weak force of attraction between the nucleus and the outermost electrons. The weaker this force, the greater the metallic character.

Metallic Character group trend

increases - shielding increases

Metallic Character period trend

Decreases - nuclear charge increases

Define electron affinity

The tendency of an atom to attract electrons, measured by the energy released when an atom gains one electron

Electron affinity group trend

Decreases - shielding increases from inner e^-

Electron affinity period trend

Increases - nuclear charge increases

Define shielding

Looks at the number of shells. More shells means less attraction

Define Nuclear Charge

If the amount of shielding is the same: a greater amount of protons means more of attraction. More electrons present, lesser attraction on each.

Metals (gain/lose) electrons, forming (positive/negative) ions.

loose, positive

Non-metals (gain/lose) electrons, forming (positive/negative) ions

gain, negative

Positive Ion term

Cation

Negative Ion term

Anion

Formula for Isotope Abundance

AAM = (% X-1)(M X-1) + (% X-2)(M X-2) + …