6.2 Chemical Building Blocks - Atomic Structure and Elements

Flashcards covering atomic structure, subatomic particles, historical atomic models, and the first 12 chemical elements based on the Jacaranda Science Quest 9 notes.

Even the largest atoms are less than __________ across.

one billionth of a metre

If an atom were the size of the MCG, the nucleus would be the size of a __________.

grain of rice

A hydrogen atom consists of about __________ empty space.

$$99.9999999999996\%$$

The relative mass of an electron is approximately __________ of a proton.

$$1/1800$$

In a neutral atom, the number of __________ equals the number of protons.

electrons

Protons and neutrons are held together in the nucleus by a __________.

strong nuclear force

The philosopher who first suggested matter is made of indestructible particles called atoms around $400$ BC was __________.

Democritus

In $1808$, __________ proposed that atoms are indivisible and combine in whole-number ratios.

Dalton

The "plum pudding" model, consisting of a positive sphere with negative electrons, was proposed by __________ in $1897$.

Thomson

In $1911$, __________ concluded the atom is mostly empty space with a small, dense, positive nucleus.

Rutherford

The model where electrons orbit at fixed energy levels by gaining or losing energy "packets" was developed by __________ in $1913$.

Bohr

The neutron was discovered in $1932$ by __________.

Chadwick

In Rutherford's experiment, a beam of positive __________ was fired at thin gold foil.

alpha particles

The symbol for gold, Au, is derived from the Latin name __________.

aurum

The __________ of an element is the number of protons in the nucleus.

atomic number

The total count of protons and neutrons in the nucleus is the __________.

mass number

The element __________ is the only one in the first $12$ with a most common neutron count of $0$.

Hydrogen

The symbol for Sodium is __________, and its atomic number is $11$.

Na

According to the first $12$ elements reference, Magnesium has a mass number of __________.

$$24$$

A substance made of only one type of atom is called an __________.

element