C1 Flashcards
All substances are made of tiny particles of matter called (?) which are the building blocks of all matter
All substances are made of tiny particles of matter called (atoms) which are the building blocks of all matter
What are the subatomic particles
Protons, neutrons and electrons
What is the centre of an atom called
The nucleus
Why is every atom neutral
The number of positive protons equals the number of negative electrons. (Neutrons are neutral)
What is thermal decomposition
The breaking down of a substance by heating (e.g. CaCO3–> CaO + CO2
What is chemical reduction
The removal of oxygen from a compound
What are the columns in the periodic table called and what do the elements in these groups have in common
The columns are called groups and in each group all of the elements in a certain group have similar chemical properties
What is Daltons model of the atom
atoms as solid spheres that could not be divided into smaller parts
What is the plum pudding model of the atom
sphere of positive charge with negative electrons embedded in it
what did scientists discover in the alpha scattering experiment
some alpha particles were deflected by the gold foil - this showed that an atoms mass and positive charge must be concentrated in one small space ( te nucleus )
describe the nuclear model of the atom
dense nucleus with electrons orbiting it
what did bohr discover
electrons orbit in fixed energy levels
what did chadwick discover
uncharged particle called the neutron
