Elements, compounds, and mixtures revision Flashcards
Element
pure substances made up of one type of atom.
Compound
A substance with two or more different types of atoms that are chemically bonded together
Pure substance
A substance made up of one type of particle. It cannot be physically separated. It can exist as either a compound or an element
mixture
A substance formed by physically mixing two different substances, and can be physically seperated
Where do elements occur on periodic table
in order of increasing atomic number
What are the vertical columns and horizontal rows on periodic table
vertical columns: groups
Horizontal rows: periods
different ways elements occurs:
single atoms, molecules, lattices
molecule:
cluster of two or more atoms bonded together
lattice
grid like structure
how many elements are there and how many occur naturally?
118 known elements, 91 occur naturally
monatomic substance
single atom
atomic number =
number of protons in a nucleus
atomic mass =
protons + neutrons
ductile
can be stretched into wires
malleable
can be bent and hammered into sheets