C1- The atom Flashcards
What is an atom?
the smallest part of an element that can exist.
What is Dalton’s Model of the atom?
Atoms as solid spheres that cannot be divided into separate parts
What is the plum pudding model of the atom?
a sphere of positive charge with negative electrons embedded
Why did scientists discover the alpha scattering experiment?
some particles were deflected by gold foil- this showed that an atom’s mass and positive charge must be concentrated in a small space (nucleus)
Describe the nuclear model of the atom.
dense nucleus with atoms orbiting
What did James Chadwick discover?
an uncharged particle (neutron)
Where are protons and neutrons
nucleus
Why do atoms have no overall charge?
they have equal numbers of positive protons and negative electrons
What is a compound?
A substance made of more than one type of atom chemically joined together
What is a mixture?
two or more substances not chemically combined
What are isotopes?
Atoms of the same element (same number of protons) with a different number of neutrons
What is relative mass?
The average mass of all the atoms in an element
