CLASS COPY

Build an AtomUnderstanding Check

  1. Build an atom in the box below that has the following components:

3 protons

4 neutrons

3 electrons

  1. Which element this atom is on this periodic table below:Lithium (Li)
  1. How many electrons in the first electron level?2
    How many valence electrons for this atom?1
  1. The atomic mass of this atom is: 7 AMU
  1. 3 amuExplain what ideas you used to choose an answer:
  2. 4 amuAtomic mass = to the # of PROTONS plus the # of NEUTRONS.
  3. 6 amu
  4. 7 amu
  1. The charge of this atom is: 0 (NEUTRAL)
  1. 0, this is a neutral atom
  2. -3
  3. -1
  4. +1
  5. +3

You start with an atom made of: 3 protons 4 neutrons 3 electrons. You want to change your atom’s properties by adding or removing sub-atomic particles (protons, neutrons and electrons.

For each question below, mark YESif a change will work, and mark NO if it will not work.

  1. If you want to change the type of element your atom is, you can either:

Add a protonYes

Add a neutronNo

Add an electronNo

Remove an electronNo

Explain the ideas you used to choose your answer:

The number of protons determine the type of atom or element it is.

  1. If you want to change the charge(make it an ion)of your atom, you can:

Add a protonNo

Add a neutronNo

Add an electronYes

Remove an electronYes

Explain the ideas you used to choose your answer:

When an atom gains or losses electrons the overall charge of the atom changes
(becomes apositively or negatively charged ion). If you change protons you change
the element.

  1. If you want to change the mass of your atom by 1 or more amu (atomic mass units), you can:

Add a protonYes

Add a neutronYes

Add an electronNo

Remove an electronNo

Explain the ideas you used to choose your answer:

The electrons contribute very little to the mass of the atom. The atomic mass of each atom is the result of the PROTONS and the NEUTRONS.

If you add 1 proton and 1 neutron to an atom of Beryllium(Be)…

  1. Will the element be Lithium, Beryllium, Boron or Carbon? BORON
  1. Will the mass change? Yes If so, what is the new mass of the atom? 11
  1. Will the charge change? Yes If so, what is the new charge of the atom?+1(no electron was added)
  1. How many valence electrons does this atom have?2 Boron should normally have 3 valence electrons, but the question only stated that Be had 1 proton and 1 neutron added (no electrons).

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