A simple model of the atom, symbols, relative atomic mass, electronic charge and isotopes key terms

Atom

The smallest part of an element that can exist. In Atoms, elements and compounds, this term helps explain define an atom as the smallest part of an element that can exist for AQA GCSE Chemistry 8462.

Element

A substance made from one type of atom, represented by a chemical symbol. In Atoms, elements and compounds, this term helps explain define an atom as the smallest part of an element that can exist for AQA GCSE Chemistry 8462.

chemical symbol

A one or two-letter notation used to represent an element, such as O for oxygen.

element

A pure substance made from one type of atom, represented in the periodic table. In Atoms, elements and compounds, this term helps explain explain that each element is represented by a chemical symbol, using examples such as O for oxygen and Na for sodium for AQA GCSE Chemistry 8462.

element

A substance made from one type of atom, represented in the periodic table. In Atoms, elements and compounds, this term helps explain describe elements as substances made from one type of atom and shown in the periodic table for AQA GCSE Chemistry 8462.

atom

The smallest part of an element that can exist. In Atoms, elements and compounds, this term helps explain describe elements as substances made from one type of atom and shown in the periodic table for AQA GCSE Chemistry 8462.

compound

A substance made from two or more elements chemically combined in fixed proportions.

element

A substance that consists of only one type of atom and is represented by a chemical symbol.

compound

A substance made from two or more elements chemically combined in fixed proportions.

chemical reaction

A process that involves the transformation of substances, allowing compounds to be separated into their constituent elements.

element

A substance made from one type of atom, represented by a chemical symbol. In Atoms, elements and compounds, this term helps explain use the names and symbols of the first 20 elements in the periodic table for AQA GCSE Chemistry 8462.

chemical symbol

A notation representing an element, such as O for oxygen or Na for sodium. In Atoms, elements and compounds, this term helps explain use the names and symbols of the first 20 elements in the periodic table for AQA GCSE Chemistry 8462.

Group 1 elements

Elements in Group 1 of the periodic table, known as alkali metals, which include lithium (Li), sodium (Na), and potassium (K).

Group 7 elements

Elements in Group 7 of the periodic table, known as halogens, which include fluorine (F), chlorine (Cl), and bromine (Br).

compound

A substance made from two or more elements chemically combined in fixed proportions.

formula

A representation of a compound using symbols for the elements and numerical subscripts to indicate the number of atoms.

word equation

A representation of a chemical reaction using the names of the reactants and products.

reactants

Substances that undergo a chemical change in a reaction. In Atoms, elements and compounds, this term helps explain write word equations for reactions in the Chemistry specification for AQA GCSE Chemistry 8462.

formula

A representation of a chemical substance using symbols for its constituent elements and numbers to indicate the ratio of atoms.

symbol equation

An equation that uses chemical symbols to represent the reactants and products in a chemical reaction.

ionic equation

An equation that shows the ions involved in a chemical reaction, indicating the charge and the species present.

half equation

An equation that shows either the oxidation or reduction process in a chemical reaction, focusing on the transfer of electrons.

mixture

A combination of two or more elements or compounds that are not chemically combined.

chemical properties

Characteristics of a substance that remain unchanged when it is part of a mixture.

mixture

A combination of two or more elements or compounds that are not chemically combined.

chemical properties

Characteristics of a substance that remain unchanged when mixed with other substances.

filtration

A separation technique that uses a barrier to separate solid particles from a liquid or gas in a mixture.

mixture

A combination of two or more elements or compounds that are not chemically combined.

crystallisation

A separation technique used to obtain dissolved solids from a solution by forming solid crystals.

dissolved solids

Substances that have been dissolved in a solvent, forming a solution. In Mixtures, this term helps explain describe crystallisation as a separation technique for dissolved solids for AQA GCSE Chemistry 8462.

simple distillation

A separation technique used to separate a liquid from a solution based on differences in boiling points.

fractional distillation

A separation technique used to separate a mixture of liquids with different boiling points into its components.

chromatography

A separation technique that involves passing a mixture through a medium where components move at different rates.

mixture

A combination of two or more elements or compounds that are not chemically combined.

mixture

A combination of two or more elements or compounds that are not chemically combined.

purification

The process of removing impurities or unwanted elements from a substance. In Mixtures, this term helps explain suggest suitable separation and purification techniques when given information about a mixture for AQA GCSE Chemistry 8462.

mixture

A combination of two or more elements or compounds that are not chemically combined.

separation technique

A method used to separate components of a mixture based on their physical properties.

scientific model

A representation or explanation of a phenomenon based on experimental evidence. In The development of the model of the atom, this term helps explain explain that new experimental evidence can change or replace a scientific model for AQA GCSE Chemistry 8462.

experimental evidence

Data and observations collected through experiments that can support or refute a scientific theory.

atom

The smallest unit of a chemical element, consisting of a nucleus surrounded by electrons.

tiny spheres

The early concept of atoms as indivisible particles with no internal structure. In The development of the model of the atom, this term helps explain describe the early idea that atoms were tiny spheres that could not be divided for AQA GCSE Chemistry 8462.

electron

A subatomic particle with a negative charge that orbits the nucleus of an atom. In The development of the model of the atom, this term helps explain describe how discovery of the electron led to the plum pudding model for AQA GCSE Chemistry 8462.

plum pudding model

An early model of the atom proposed by J.J. Thomson, suggesting that electrons are embedded in a positively charged 'soup'.

plum pudding model

An early model of the atom where electrons are embedded in a positively charged 'soup'.

nuclear model

A model of the atom that describes a dense nucleus containing protons and neutrons, with electrons orbiting around it.

alpha particle scattering

An experiment that demonstrated the existence of a small, dense nucleus in atoms, leading to the rejection of the plum pudding model.

plum pudding model

An early model of atomic structure that proposed atoms were composed of a positively charged 'soup' with negatively charged electrons embedded within.

nuclear model

A model of the atom that places most atomic mass and positive charge in the nucleus.

nucleus

The central part of an atom containing protons and neutrons, which holds most of the atom's mass.

Bohr model

A model of the atom where electrons are placed at specific distances from the nucleus.

nuclear model

A representation of the atom that places most atomic mass and positive charge in the nucleus.

proton

A subatomic particle found in the nucleus of an atom, carrying a positive electrical charge.

nuclear model

A model of the atom that places most of the atomic mass and positive charge in the nucleus, with electrons orbiting around it.

neutron

A subatomic particle found in the nucleus of an atom, with no electrical charge.

Chadwick's work

Research conducted by James Chadwick that provided evidence for the existence of neutrons in the atomic nucleus.

atomic model

A theoretical representation of the structure and behavior of atoms, illustrating how scientific understanding has evolved over time.

scientific method

A systematic approach used in scientific inquiry to develop theories and models based on evidence and experimentation.

proton

A subatomic particle found in the nucleus of an atom, with a relative electrical charge of +1.

relative electrical charge

The charge of a subatomic particle compared to the charge of a proton, used to describe the charge of particles like electrons and neutrons.

neutron

A subatomic particle found in the nucleus of an atom, with no electrical charge.

relative electrical charge

The measure of the electric charge of a particle compared to the charge of a proton.

electron

A subatomic particle with a relative electrical charge of -1. In Relative electrical charges of subatomic particles, this term helps explain state the relative electrical charge of an electron for AQA GCSE Chemistry 8462.

relative electrical charge

The measure of the electric charge of a subatomic particle compared to a proton.

proton

A positively charged subatomic particle found in the nucleus of an atom. In Relative electrical charges of subatomic particles, this term helps explain explain why atoms have no overall electrical charge when the number of electrons equals the number of protons for AQA GCSE Chemistry 8462.

electron

A negatively charged subatomic particle that orbits the nucleus of an atom. In Relative electrical charges of subatomic particles, this term helps explain explain why atoms have no overall electrical charge when the number of electrons equals the number of protons for AQA GCSE Chemistry 8462.

atomic number

The number of protons in an atom of an element. In Relative electrical charges of subatomic particles, this term helps explain define atomic number as the number of protons in an atom of an element for AQA GCSE Chemistry 8462.

proton

A positively charged subatomic particle found in the nucleus of an atom. In Relative electrical charges of subatomic particles, this term helps explain define atomic number as the number of protons in an atom of an element for AQA GCSE Chemistry 8462.

proton

A positively charged subatomic particle found in the nucleus of an atom. In Relative electrical charges of subatomic particles, this term helps explain explain why atoms of the same element have the same number of protons for AQA GCSE Chemistry 8462.

element

A substance that consists of only one type of atom, characterized by its number of protons.

proton

A positively charged subatomic particle found in the nucleus of an atom. In Relative electrical charges of subatomic particles, this term helps explain explain why atoms of different elements have different numbers of protons for AQA GCSE Chemistry 8462.

atomic number

The number of protons in an atom of an element, which determines the element's identity.

nucleus

The central part of an atom, containing protons and neutrons. In Relative electrical charges of subatomic particles, this term helps explain use the nuclear model to describe atoms in terms of nucleus and electrons for AQA GCSE Chemistry 8462.

electron

A negatively charged subatomic particle that orbits the nucleus of an atom. In Relative electrical charges of subatomic particles, this term helps explain use the nuclear model to describe atoms in terms of nucleus and electrons for AQA GCSE Chemistry 8462.

atomic radius

the distance from the nucleus to the outermost electron shell, approximately 0.1 nm.

nucleus

the central part of an atom, containing protons and neutrons, and much smaller than the atom itself.

atomic radius

The distance from the nucleus to the outermost electron shell of an atom, typically measured in nanometers.

standard form

A way of expressing numbers that are too large or too small to be conveniently written in decimal form, using powers of ten.

nucleus

The central part of an atom, containing protons and neutrons, and is much smaller than the atom itself.

atomic radius

The size of an atom, typically measured as about 0.1 nm. In Size and mass of atoms, this term helps explain state that a nucleus is much smaller than an atom, with a radius of about 1 x 10^-14 m for AQA GCSE Chemistry 8462.

nucleus

The central part of an atom where almost all its mass is concentrated. In Size and mass of atoms, this term helps explain explain that almost all the mass of an atom is concentrated in the nucleus for AQA GCSE Chemistry 8462.

mass

The amount of matter in an atom, primarily found in the nucleus. In Size and mass of atoms, this term helps explain explain that almost all the mass of an atom is concentrated in the nucleus for AQA GCSE Chemistry 8462.

Proton

A subatomic particle with a positive charge found in the nucleus of an atom. In Size and mass of atoms, this term helps explain state the relative masses of protons, neutrons and electrons for AQA GCSE Chemistry 8462.

Neutron

A subatomic particle with no charge, also located in the nucleus of an atom. In Size and mass of atoms, this term helps explain state the relative masses of protons, neutrons and electrons for AQA GCSE Chemistry 8462.

mass number

The total number of protons and neutrons in an atom. In Size and mass of atoms, this term helps explain define mass number as the total number of protons and neutrons in an atom for AQA GCSE Chemistry 8462.

protons

Positively charged subatomic particles found in the nucleus of an atom. In Size and mass of atoms, this term helps explain define mass number as the total number of protons and neutrons in an atom for AQA GCSE Chemistry 8462.

isotope

Atoms of the same element with different numbers of neutrons. In Size and mass of atoms, this term helps explain define isotopes as atoms of the same element with different numbers of neutrons for AQA GCSE Chemistry 8462.

mass number

The total number of protons and neutrons in an atom. In Size and mass of atoms, this term helps explain define isotopes as atoms of the same element with different numbers of neutrons for AQA GCSE Chemistry 8462.

isotope notation

A way of representing isotopes that shows the atomic number and mass number of an atom.

atomic number

The number of protons in the nucleus of an atom, which determines the element's identity.

mass number

The total number of protons and neutrons in an atom. In Size and mass of atoms, this term helps explain calculate the number of protons, neutrons and electrons in an atom from atomic number and mass number for AQA GCSE Chemistry 8462.

atomic number

The number of protons in the nucleus of an atom, which determines the element. In Size and mass of atoms, this term helps explain calculate the number of protons, neutrons and electrons in an atom from atomic number and mass number for AQA GCSE Chemistry 8462.

protons

Positively charged subatomic particles found in the nucleus of an atom. In Size and mass of atoms, this term helps explain calculate the number of protons, neutrons and electrons in an ion from atomic number, mass number and charge for AQA GCSE Chemistry 8462.

mass number

The total number of protons and neutrons in an atom. In Size and mass of atoms, this term helps explain calculate the number of protons, neutrons and electrons in an ion from atomic number, mass number and charge for AQA GCSE Chemistry 8462.

SI units

Standardized units of measurement used to describe physical quantities, including atomic size.

nano prefix

A metric prefix indicating a factor of 10^-9, commonly used to express atomic dimensions.

atomic scale

The size of atoms compared to everyday objects, illustrating their minuscule dimensions.

physical world comparison

The method of relating atomic sizes to larger objects to understand their scale.

relative atomic mass

An average value that accounts for the abundance of different isotopes of an element.

isotope abundance

The relative amount of each isotope of an element present in a sample. In Relative atomic mass, this term helps explain define relative atomic mass as an average value that accounts for isotope abundance for AQA GCSE Chemistry 8462.

relative atomic mass

The weighted average mass of an atom of an element compared to 1/12th the mass of a carbon-12 atom.

isotope

Atoms of the same element with the same number of protons but different numbers of neutrons.

relative atomic mass

The weighted average mass of an atom of an element compared to 1/12th of the mass of a carbon-12 atom.

percentage abundance

The relative amount of each isotope of an element present in a sample, expressed as a percentage.

relative atomic mass

The weighted average mass of an element's isotopes compared to one twelfth of the mass of carbon-12.

isotope abundance

The relative amount of a particular isotope of an element compared to the total amount of all isotopes of that element.

energy level

A region around the nucleus of an atom where electrons are likely to be found, with lower energy levels being filled before higher ones.

innermost shell

The closest shell to the nucleus of an atom, which is filled with electrons before any electrons occupy higher energy levels.

electronic structure

The arrangement of electrons in an atom, represented by numbers indicating the number of electrons in each energy level.

sodium

A chemical element with the symbol Na and atomic number 11, represented in electronic structure as 2,8,1.

electronic structure

The arrangement of electrons in an atom, typically represented by numbers indicating the number of electrons in each energy level.

first 20 elements

The first 20 elements of the periodic table, which include hydrogen to calcium, used for representing electronic structures in diagrams.

electron-shell diagram

A visual representation showing the arrangement of electrons in an atom's energy levels.

first 20 elements

The first 20 elements of the periodic table, which include hydrogen to calcium, used for basic electronic structure interpretation.

outer-shell electrons

Electrons located in the outermost energy level of an atom, which determine its chemical properties.

electronic structure

The arrangement of electrons in an atom's energy levels or shells, which influences its reactivity and bonding.