Chemistry Study Notes
Chemistry
• Element – pure substances that cannot be broken down into simpler substances. Made up of particles/atom of only one kind. Simplest pure substances.
• Compounds – pure substances which contain two or more different elements.
• Atom – smallest particle of an element. The smallest unit of an element that maintains the properties of that element.
• Chemical Group – the set of elements in the same column of the periodic table. These elements have similar physical and chemical properties.
• Isotope – An isotope of an element has different number of neutrons.
• Radioisotopes – Some isotopes are unstable, which means that the nucleus has a tendency to break apart and eject particles. Atoms that have unstable nucleus are called radioisotopes.
• Subatomic particles – the particles of which an atom is made of are the subatomic particles.
• Excited state – When electrons are energized by heat, electricity or light, they use the extra energy to jump in an higher orbit.
• Ground state – low-energy state of an electron.
• Spectrum – a rainbow of many colours that combine to make white light.
• Molecule – Atoms join together to form molecules.
• Corrosion – the slow chemical change that occur when a metal reacts with oxygen to form a new substance – oxide.
• Combustion – substance reacts rapidly with oxygen, releasing large amounts of energy.
• Atomic Number – the number of protons in an atom.
• Mass Number – the sum of protons and neutrons in the nucleus of an atom.
• Precipitate – a solid, insoluble material that forms in a liquid solution.
Properties of Matter
• Malleability – ability of a substance to be hammered or bent into different shapes. Ex: Aluminum foil.
• Viscosity – a measure of how easily a liquid flows. The thicker the liquid, the more viscous it is.
• Ductility – ability to be drawn into thin wires. Ex: Copper.
• Lustre – quality or state of shining. Ex: Gold.
• Density – amount of matter per unit volume. Measured in kg/cm3,
• Element – pure substances that cannot be broken down into simpler substances. Made up of particles/atom of only one kind. Simplest pure substances.
• Compounds – pure substances which contain two or more different elements.
• Atom – smallest particle of an element. The smallest unit of an element that maintains the properties of that element.
• Chemical Group – the set of elements in the same column of the periodic table. These elements have similar physical and chemical properties.
• Isotope – An isotope of an element has different number of neutrons.
• Radioisotopes – Some isotopes are unstable, which means that the nucleus has a tendency to break apart and eject particles. Atoms that have unstable nucleus are called radioisotopes.
• Subatomic particles – the particles of which an atom is made of are the subatomic particles.
• Excited state – When electrons are energized by heat, electricity or light, they use the extra energy to jump in an higher orbit.
• Ground state – low-energy state of an electron.
• Spectrum – a rainbow of many colours that combine to make white light.
• Molecule – Atoms join together to form molecules.
• Corrosion – the slow chemical change that occur when a metal reacts with oxygen to form a new substance – oxide.
• Combustion – substance reacts rapidly with oxygen, releasing large amounts of energy.
• Atomic Number – the number of protons in an atom.
• Mass Number – the sum of protons and neutrons in the nucleus of an atom.
• Precipitate – a solid, insoluble material that forms in a liquid solution.
Properties of Matter
• Malleability – ability of a substance to be hammered or bent into different shapes. Ex: Aluminum foil.
• Viscosity – a measure of how easily a liquid flows. The thicker the liquid, the more viscous it is.
• Ductility – ability to be drawn into thin wires. Ex: Copper.
• Lustre – quality or state of shining. Ex: Gold.
• Density – amount of matter per unit volume. Measured in kg/cm3,