Topic 1 - Key Concepts in Chemistry Flashcards
What is an Anion?
A negatively charged ion formed when an atom gains at least one electron.
What is an Atom?
The smallest part of an element that can exist. All substances are made up of atoms.
What is an Atomic nucleus?
A positively charged object composed of protons and neutrons at the centre of every atom with one or more electrons orbiting it.
What is Atomic number?
The number of protons in the nucleus.
What is Avogadro’s constant?
The number of atoms, molecules or ions in a mole of a given substance.
What is a Cation?
A positively charged ion formed when an atom loses at least one electron.
What is a Compound?
A substance made up of two or more types of atoms chemically combined together.
What is Concentration?
The amount of substance (e.g. the mass) in a certain volume of a solution.
What is a Conductor?
A material that contains charged particles which are free to move to carry electrical or thermal energy.
What is the Conservation of mass?
A law which states that no atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants.
What is a Covalent bond?
A shared pair of electrons between two non-metals.
What is the Dalton model?
Dalton described atoms as solid spheres, stating that different spheres made up the different elements.
What is Diamond?
A giant covalent structure made up of carbon atoms each of which form four covalent bonds with four other carbon atoms.
What is an Electron?
Negatively charged subatomic particle which orbit the nucleus at various energy levels. Very small relative mass (negligible).
What is an Electron shell?
Different energy levels in atoms occupied by electrons.
What are Electrostatic forces?
The strong forces of attraction between oppositely charged ions.
What is an Element?
A substance made up of only one type of atom.
What is an Empirical formula?
The simplest whole number ratio of atoms of each element in a compound.
What are Fullerenes?
Molecules of carbon atoms with hollow shapes based on hexagonal rings of carbon atoms, may also contain rings with five or seven carbon atoms.
Examples include graphene and C60.
What is a Giant covalent molecule?
Molecules containing many atoms covalently bonded together.
What is Graphene?
A single layer of graphite with properties that make it useful in electronics and composites.
What is Graphite?
A giant covalent structure made up of carbon atoms each of which form three covalent bonds with three other carbon atoms, forming layers of hexagonal rings with no covalent bonds between them.
What is a Group in the periodic table?
A column of the periodic table. Elements in the same group have similar chemical properties.
What are Intermolecular forces?
The forces which exist between molecules, impacting physical properties like boiling/melting point.
What is an Ion?
An atom or molecule with an electric charge due to the loss or gain of electrons.
What is an Ionic bond?
The bond formed between oppositely charged ions when a metal atom loses electron(s) to form a positively charged ion and a non-metal gains these electron(s) to form a negatively charged ion.
What is an Ionic compound?
Chemical compound formed of oppositely charged ions, held together by strong electrostatic forces.
What is an Isotope?
Atoms of the same element with the same number of protons but a different number of neutrons.
What is a Lattice?
A repeating regular arrangement of atoms/ions/molecules occurring in crystal structures.
What is a Limiting reactant?
The reactant that is completely used up since it limits the amount of products formed.
What is Mass number?
The total number of protons and neutrons in the nucleus.
What is a Metallic bond?
The bonds present in metals between the positive metal ions and negatively charged electrons.
What are Metals?
Elements that react to form positive ions, found to the left and towards the bottom of the periodic table.
What is a Mole?
The unit for amount of substance. The symbol for the unit mole is mol.
What is a Molecular formula?
The actual ratio of atoms of each element present in a compound.
What is a Molecule?
A group of at least two atoms held together by covalent bonds.
What is a Neutron?
Neutral subatomic particle present in the nucleus of the atom. Relative mass of 1.
What are Non-metals?
Elements that react to form negative ions, found towards the right and top of the periodic table.
What is a Period in the periodic table?
A row of the periodic table. Elements in the same period have the same number of electron shells.
What is the Periodic table?
Table of elements arranged in order of increasing atomic number with elements of similar properties in the same column (group).
What are Polymers?
Large long-chain molecules made up of lots of small monomers joined together by covalent bonds.
What is a Proton?
Positively charged subatomic particle present in the nucleus of the atom. Relative mass of 1.
What is Relative atomic mass?
An average value that takes into account the abundances of the isotopes of the element.
What is Relative formula mass?
The sum of the relative atomic masses of the atoms in the numbers shown in the formula, equal to the mass of one mole of a substance in grams.
What are Simple molecules?
Molecules containing a fixed number of atoms covalently bonded together.
What are Subatomic particles?
Particles smaller than an atom. Protons, neutrons, and electrons are the three most common subatomic particles.
