Topic 1: Key Concepts in Chemistry Flashcards
(13 cards)
What is an element?
A substance made of only one type of atom.
Elements are the simplest form of matter and cannot be broken down into simpler substances.
What is a compound?
A substance made from two or more elements chemically bonded.
Compounds have unique properties that differ from the individual elements.
Where are electrons found in an atom?
In shells (energy levels) around the nucleus.
Electrons occupy different energy levels based on their energy.
What is the relative charge of a proton, neutron, and electron?
Proton: +1, Neutron: 0, Electron: -1
The charges determine the atom’s overall charge and interactions with other atoms.
What is the atomic number?
The number of protons in an atom.
The atomic number defines the element and its position in the periodic table.
What is the mass number?
The total number of protons and neutrons in an atom.
Mass number is used to identify isotopes of an element.
What is an isotope?
Atoms of the same element with different numbers of neutrons.
Isotopes have the same chemical properties but different physical properties.
What type of bonding occurs between a metal and a non-metal?
Ionic bonding.
Ionic bonds involve the transfer of electrons from one atom to another.
What type of bonding occurs between two non-metals?
Covalent bonding.
Covalent bonds involve the sharing of electron pairs between atoms.
What is a polymer?
A long chain molecule made of repeating units (monomers).
Polymers can be natural or synthetic and have various applications.
What is the law of conservation of mass?
Mass cannot be created or destroyed in a chemical reaction.
This principle is fundamental in chemical equations and stoichiometry.
What is the relative formula mass (Mr)?
The sum of the relative atomic masses of all atoms in a compound.
It is used to calculate the mass of substances in chemical reactions.
What is a mole?
The amount of substance containing 6.02 × 10²³ particles.
This number is known as Avogadro’s number and is fundamental in chemistry.
