Chemistry - Chap 5 Flashcards
Alkali metals
Low melting point and react easily with water and air, very soft
- shiny, silvery metals
- extremely reactive
- combine easily with other elements to form compounds
Atom
Smallest part of an element that has all of the elements properties
Atomic mass
Average mass of an elements atoms
Atomic number
Number of protons in an atom of an element
Atomic theory
Study of the nature of atoms and how they combine to form all types of matter
Group (chemical family)
Classification of elements with certain shared physical and chemical properties
Halogens
Non-metals, very reactive and have a noticeable colour, growing in intensity
Ion
Atom or group of atoms that has lost or gained electrons
Ion charge
Electric charge that an atom or group of joined atoms take on when it loses or gains electrons
Metal
Element that is malleable and ductile and conducts electricity and heat
Metalloids
Element with metallic and non-metallic properties (silicon)
Noble gases
Elements that glow if an electric current is passed through them, none of these gases are chemically reactive reactive, rarely form chemical compounds with other elements
Non-metals
Elements that are grouped together mainly because they do not resemble metals (carbon)
Nucleus (atomic)
Centre of the atom, contains protons and electrons
Period
One of seven horizontal rows in the periodic table
Property
Characteristic that describes a substance
Pure substance
One kind of matter with a unique set of properties
Relative mass
Mass of an object in comparison to the mass of another object
Solution
Combination of pure substances in which the different substances are not individually visible (homogeneous)
Subatomic particles
Particles that make up an atom (including protons, neutrons, and electrons)
Sublimation
Change of state from a solid into a gas
Suspension
Cloudy mixture in which tiny particles of one substance are held within another (type of heterogeneous)
Valence electrons
Electron in the valence shell of an atom
Valence shell
Outermost shell or energy level of an atom that has electrons in it