Model of atom, sixe and subatomic particles - Atomic structure Flashcards
What are the charges of the three subatomic particles?
Protons - +1
Neutrons - 0
Electrons - -1.
What’s the mass of the subatomic particles?
Protons - +1
Neutrons - +1
Electrons - Almost 0.
Facts about the nucleus
In middle of atom
Contains protons and neutrons
Radius of around 1 x 10-14
Positive charge because of protons
Almost whole mass of atom is in nucleus.
What does the atomic number represent?
Number of protons
Or number of electrons
What does the mass number represent?
Number of Protons + neutrons
How do you work out the amount of neutrons in an atom from the nuclear symbol?
mass number - atomic number.
What two subatomic particles always have the same value?
(Unless an ion)
Protons and Electrons
Why do ions make it so electrons and protons aren’t same amount?
In an ion, number of protons doesn’t equal number of electrons.
E.g i. a -2 charged ion, it has two more electrons than protons.
How do you find out the number of electrons in a positive ion?
Number of electrons = atomic number - charge
How do you find out the amount of electrons in a negative ion,
Number of electrons = atomic number + charge
What did the plum pudding model show?
Who created it?
Plum pudding model showed the atom as a ball of positive charge with electrons scattered in the ball.
Made by J.J Thompson
Who made the current nuclear model?
Bohr.
What did Chadwick find out?
Nucleus containing neutrons and protons.
How many electrons are in 1st, 2nd and 3rd shell?
2, 8, 8.
