Year 10 Triple Chemistry - Atomic Structure and Periodic Table Review

Vocabulary flashcards generated from Year 10 Triple Chemistry notes covering subatomic particles, atomic models, Rutherford's experiment, Group 2 metals, electronic configuration, Mendeleev and modern periodic tables, fuel cells, and relative atomic mass.

Atomic Number

The number of protons in the nucleus of an atom, represented by the lower subscript number on the periodic table.

Mass Number

The total number of protons and neutrons in the nucleus of an atom.

Proton

A subatomic particle found in the nucleus with a relative charge of $+1$ and a relative mass of $1$.

Neutron

A subatomic particle found in the nucleus with a relative charge of $0$ and a relative mass of $1$.

Electron

A subatomic particle located in shells around the nucleus with a relative charge of $-1$ and a relative mass of $\frac{1}{1840}$ ($0.0005$).

Dalton's Atomic Model

An atomic model proposed in 1803 stating that all matter is made of indivisible spherical atoms that cannot be created or destroyed, and that all atoms of a given element are identical.

Modern Atomic Model

An atomic model stating that atoms consist of smaller subatomic particles (protons, neutrons, electrons), can vary as isotopes, and are mostly empty space with a small, dense, positively charged nucleus.

Rutherford's Gold Foil Experiment

An experiment where positively charged alpha particles were fired at thin gold foil; most passed straight through, showing atoms are mostly empty space, while a small fraction ($1$ in $8000$) deflected due to a tiny, dense, positively charged nucleus.

Group 2 (The Alkaline Earth Metals)

A group of shiny, silver-white metals (Beryllium, Magnesium, Calcium, Strontium, Barium) that are good conductors, react with water to form metal hydroxides and hydrogen, react with oxygen to form metal oxides, increase in reactivity down the group, and form $+2$ ions.

Electronic Configuration Rules

The rules governing electron shell filling: inner shells fill first, with up to $2$ electrons in the 1st shell, up to $8$ in the 2nd shell, and up to $8$ in the 3rd shell.

Mendeleev's Periodic Table

A historical periodic table where elements were arranged in order of atomic mass, grouped by similar properties, and gaps were left to accurately predict undiscovered elements.

Modern Periodic Table

The table of elements arranged by atomic number rather than atomic mass, organized by electronic configuration, with elements in the same group sharing the same number of outer shell electrons.

Fuel Cell

A device that converts chemical energy directly into electrical energy using fuel (such as hydrogen) and oxygen, producing power continuously without polluting as its only byproduct is water ($H_2O$).

Hydrogen Fuel Cell Reaction

The chemical reaction represented by the word equation Hydrogen + Oxygen $\rightarrow$ Water, and the chemical equation $2H_2 + O_2 \rightarrow 2H_2O$.

Isotopes

Atoms of the same element that have the same number of protons but a different number of neutrons, leading to different mass numbers.

Relative Atomic Mass ($A_r$)

The weighted average mass of the atoms of an element compared to $\frac{1}{12}$th of the mass of a carbon-12 atom, calculated using the formula $A_r = \frac{\frac{\text{sum of } (\text{isotope mass} \times \text{abundance})}{\text{total abundance}}}{1}$.