CHEMISTRY 12 - Assessment No.3

1ST SEM MID-TERM

Isotopes

are atoms of the same element (same number of protons) with different numbers of neutrons (which changes their atomic mass)

Empirical

Simplest whole number ratio of elements

Molecular

Actual whole number ratio, multiple of empirical

Atomic mass

it is the mass of an atomic which is expressed in atomic mass unit (amu) and used the most abundant element of carbon, carbon 12

Atomic mass unit (amu)

defined as 1/12 of the mass of C-12 isotope

Percent abundance

the percentage of a naturally occurring element’s atomics that are a specific isotope

Average Atomic Mass

It’s a weight average of the mass numbers of an element’s isotopes, taking into account their natural abundance, and is found on the periodic table (A_r)

Formula/Molecular Mass

It is the sum of the atomic masses of all atoms in the formula

Protium

The isotope name if Hydrogen has 0 neutrons

Deuterium

The isotope name if Hydrogen has 1 neutron

Tritium

The isotope name if Hydrogen has 2 neutrons

Condensed

Shows group order without drawing bonds

Structural

Complete 2D visual drawing showing all bonds

Protons

It is a subatomic particle that defines the element (Atomic Number, Z) and has a positive charge

Proton

It is a subatomic particle that defines the element (Atomic Number, Z) and has a positive charge

Neutron

It is a subatomic particle that has a neutral charge and contributes to the mass number

Electron

It is a subatomic particle that contributes to the electric charge of an atom and has a negative charge

Complete Combustion

• happens when there is a good or sufficient supply of air or oxygen

• the maximum amount of energy is  given out  (exothermic process)

• carbon dioxide and water are produced

Incomplete Combustion

• happens when the supply of air or oxygen is poor or insufficient.

• less energy is released than during complete combustion

Ion

is an atom (or group of bonded atoms) that has acquired a net electrical charge by gaining or losing one or more electrons

Cation

Formed when an atom LOSES electrons making it a positive ion

Anion

Formed when an atom GAINS electrons making it a negative ion

Covalent Compounds

combination of two or more NONMETALS covalently bonded ( involves sharing of electrons)

Ionic compounds

• results from the attraction between a cation and an anion

• is NEUTRAL, the ratio where the total positive and negative charges of the ions SUM UP to ZERO.

Monatomic ions

A single, individual atom or element that has a negative or positive charge

Polyatomic ions

It’s 2 or more atoms stuck together acting as one group with a charge

Arrhenius acid

substance that yields H⁺ in aqueous solution

Strong Acid

is one that completely ionizes (dissociates) in water, releasing all of its hydrogen ions (H⁺).