What do you notice about the number
of quarks in the neutron and proton?
Sub-Atomic Particles Weight Comparison (protons, neutrons, electrons)
Neutron = 1.6749286 x10-27 kg Proton = 1.6726231 x10-27 kg Electron = 9.1093897 x10-31 kg
1836 electrons = 1 proton
1839 electrons = 1 neutron
How do you think the mass of a neutron
compares to that of a proton?
1 neutron ≈ 1 proton
Sub-atomic Particles Size Comparison (protons, neutrons, electrons, & quarks)
The number of protons in the nucleus of an atom
What would be the atomic number of this atom?
The total number of protons and neutrons in an atom’s nucleus
Expressed in Atomic Mass Units (amu)
Each proton or neutron has a mass of 1 amu
What would be the mass number of this atom?
3 protons + 4 neutrons = a mass number of 7 amu
Why did we not account for the electrons when calculating the mass number?
Using the whiteboard and the proton, neutron, and electron pieces, build the following atoms, and determine their atomic and mass numbers.
Using the interactive website link below, practice building atoms.
Using the classzone.com link below, click on the “Build an Atom” simulation and practice building atoms.
FORCES IN THE ATOM
The force of attraction of objects due to their masses
The amount of gravity between objects depends on their masses and the distance between them
Do you think this force plays a significant
role in holding the atom together?
The force that results from the repulsion of like charges and the attraction of opposites