Structure Of An Element

Question 1

Representing Atoms

Answer 1

• energy levels = shells = orbitals
• electrons in levels that are farther from the
  nucleus have more energy than electrons in levels
  that are closer to the nucleus.
• according to Bohr, each energy level can only
  hold a maximum number of electrons.
• number of electrons that can occupy each energy
  level changes as you move outward from the
  nucleus
• 1
  st level = 2 electrons max
• 2
  nd level = 8 electrons max
• 3
  rd level = 8 electrons max
• 4
  th level = 18 electrons mx

Question 2

protons and neutrons

Answer 2

Protons and neutrons contribute nearly all of the mass of an atom.
Neutrons have slightly more mass than protons, but both protons and
neutrons have about 1840 times more mass than electrons.
Protons and Neutrons

The mass number of an element is the sum of the number of protons
and neutrons in the element’s nucleus.
The atomic number of an element is equal to the number of protons
in the element’s nucleus.

Question 3

How to calculate the number of subatomic particles

Answer 3

atomic number=number of protons
mass number=number of protons+ number of neutrons
number of neutrons=mass number-atomic number
number of protons=number of electrons(neutral atom)

Question 4

Element information

Answer 4

-top left number= atomic number(p+)
-top right number= ion charge
-symbol:eg bismuth’s -symbol would be Bi
-name of element
bottom number=atomic mass (p+ plus n0)

Question 5

Element information( memorize the eg)

Answer 5

• Atomic number (top left corner) = # protons
  (Eg. magnesium-12 = 12 protons)
  ▪ # protons = # electrons
  (Eg. sulfur 16 = 16 protons & 16 electrons)
  ▪ mass number = # protons + # neutrons
  to calculate # neutrons = mass # - atomic #
  (Eg. Neutrons in chlorine = 35 – 17

= 18 neutrons)

Question 6

Protons and neutrons

Answer 6

• Neutrons and protons do not attract each
  other.
• Nucleus is held together by the strong force;
  the strongest force in nature.
• This force overcomes the repulsion between
  positively charged protons.
• Protons and neutrons make up the nucleus
  and are sometimes referred to as nucleons.

Question 7

Strong force

Answer 7

Electric Repulsion of protons strains the Nucleus
But the (residual:. pertaining to or constituting a residue or remainder; remaining; leftover) strong nucleus force holds the nucleus together.

Question 8

Representing Atoms

Answer 8

The Bohr-Rutherford model is a convenient way of representing the
structure of an atom. These models, as illustrated below, show the
numbers of protons and neutrons in the nucleus and place the electrons
in the energy levels (shells) they occupy, outside the nucleus.

Question 9

review how to draw a Bohr Rutherford diagram (for the first twenty elements)

Answer 9

chapter 5 notes