Atomic Structure Flashcards
State the radius of an atom
1 x 10(-10) meters
State the radius of a typical nucleus
1 x 10(-14) metres
How does the radius of a nucleus compare to that of an atom
At least 10,000 times smaller
Where is most of the mass concentrated in an atom
The nucleus
How are electrons arranged in atoms?
They orbit the nucleus in energy levels
What happens when an electron absorbs EM radiation?
They get excited and move to a higher energy level
What happens when an electron emits EM radiation
It becomes de-excited and moves to a lower energy level
State the mass of a proton
1
State the mass of a neutron
1
State the mass of an electron
1/2000
state the charge of a proton
+1
State the charge of an electron
-1
State the charge of a neutron
0
State where the protons are found
The nucleus of the atom
State where the protons are found
Nucleus
State where the electrons are found
In energy levels orbiting the nucleus
What does the atomic number tell us?
The number of protons which determines what is the element is
What does the mass number tells us?
The sum of protons and neutrons in the nucleus
How can we calculate the number of neutrons in atom has
By subtracting the atomic proton number from the atomic mass number
State why the atoms have no overall charge
They have the same number of positive protons and a negative electrons of the charges cancel out
Define ion
A charged particle that has either gained or lost an electron
How can atoms turn into positive ions?
They lose one or more outer electrons
Define isotope
Atoms of the same element with the same number of protons, but different number of neutrons
What can led to the scientific model being replaced?
New experimental evidence
Before the electron were discovered atoms what we are atoms thought to be
Tiny indivisible Spears