C1 - Atomic Struxture Flashcards
(20 cards)
What is the relative charge and mass of a proton?
Charge = +1, Mass = 1
What is the relative charge and mass of a neutron?
Charge = 0, Mass = 1
What is the relative charge and mass of an electron?
Charge = -1, Mass = ~0 (very small)
What is the atomic number of an element?
The number of protons in the nucleus.
What is the mass number of an atom?
The total number of protons and neutrons.
How do you calculate the number of neutrons in an atom?
Neutrons = Mass number - Atomic number
What is an isotope?
Atoms of the same element with the same number of protons but different numbers of neutrons.
Why do isotopes have the same chemical properties?
Because they have the same number of electrons.
How were atoms arranged in Dalton’s model?
As solid spheres.
What did the plum pudding model suggest about the atom?
That it was a ball of positive charge with electrons scattered throughout.
What experiment led to the nuclear model of the atom?
The alpha particle scattering experiment by Rutherford.
What did Rutherford’s model propose?
That atoms have a small, dense, positively charged nucleus and electrons orbit around it.
How did Bohr improve the atomic model?
He proposed that electrons orbit the nucleus in fixed energy levels (shells).
Why was the neutron the last subatomic particle to be discovered?
Because it has no charge, making it harder to detect.
What are the maximum number of electrons in the first three shells?
1st = 2, 2nd = 8, 3rd = 8
What is the electron configuration of an atom with atomic number 11?
2,8,1 (sodium)
What is the overall charge of an atom? Why?
0, because it has equal numbers of protons and electrons.
What is the difference between an atom and an ion?
Atoms are neutral; ions have lost or gained electrons and are charged.
What happens when a metal atom forms a positive ion?
It loses electrons.
Why are models of the atom still used in science today?
They help explain and predict chemical behavior, even though they are simplified representations.
