C3) Atoms, Elements, & Compounds Flashcards
define an element. [1]
made of one type of atom
define a compound [1]
made of more than one type of atom chemically bonded together
define a mixture [1]
2 or more elements/ compounds mixed together that can be separated by physical means
describe properties of metals [7]
- usually solids at room temp.
- malleable
- ductile
- shiny
- high melting & boiling point
- high density
- good thermal & electrical conductivity
what is the difference between a physical change and a chemical change?
physical change = change in state
chemical change = atleast 1 new substance is amde
what is the difference in colour between anhydrous and hydrated forms of copper (II) sulphate?
anhydrous copper sulfate = white
hydrated copper sulphate = blue
what is the difference in colour between anhydrous and hydrated forms of cobalt (II) chloride?
anhydrous cobalt chloride = blue
hydrated cobalt chloride = pink
what is the mass number of an element?
number of nucleons (protons + neutrons)
how are elements arranged in the periodic table?
in ascending atomic number
define an isotope
atoms of the same element with same number of protons and electrons, but diff number of neutrons
why do isotopes have the same chemical properties?
bc they have the same number of electrons in their outer shell
how do metal atoms form ions?
lose electrons to form positive ions
how do non-metal atoms form ions?
gain electrons to form negative ions
describe an ionic bond
the electrostatic attraction between positive metal ions and negative non metal ions
what type of structure do ionic substances form?
giant ionic lattices