Chemistry Flashcards
(21 cards)
Physical properties
Describe the physical appearance and composition of a surface
Eg: Mass, colour, hardness, temperature, malleability
Physical change
When physical properties change
Chemical properties
Any property that changes the bonds of the molecule. Describe the reactivity of a substance.
Atoms
The smallest part of an element that retains the chemical and physical properties of an element
Dalton’s Atomic Theory
Matter is composed of tiny, indivisible particles called atoms
JJ Thompson
Created the discovery of atoms
Ernest Rutherford
Performed an experiment that led to the discovery of the nucleus of the atom
- Positive centre surrounded by electrons
Neils Bohr
Proposed that electrons surrounded the nucleus at specific energy levels
Quantum Mechanical Model of the Atom
Present day models of the atom are much more complex
Energy levels
Region of space near a nucleus that may be empty or may contain electrons
Atomic number
number of protons an element has
Isotope
Atoms of the same element with different numbers of neutrons
Nuclear notation
Mass number = neutrons + atomic number
Periodic table organization
Elements are organized in order of number of electrons
Cations
Positively charged ions have fewer electrons than protons
Anions
negatively charged ions have more electrons than protons
Polyatomic Ions
Consist of one or more different atoms covalently bonded and containing an overall charge
Molecular Compounds
Atoms that share electrons to become stable form molecular compounds
Molecular Bonding
Atoms in molecules are joined by covalent bonds
Binary molecular compounds
When two non-metallic atoms join by covalent bonds
Binary Molecular Compounds
When two non metallic elements join by a covalent bond
