Well we can't see the picture that the teacher has, and we have to figure out what's in the picture from some clues in the answer choices. The picture seems to show an atom with 3 protons and 3 neutrons in the nucleus, and 3 electrons whizzing around the nucleus.
If that's what's in the picture, then Mike is correct (first choice), because the atomic number shows the number of protons in all atoms. There are 3 protons and the atomic number of lithium is 3.
Second choice . . . False, because electrons are not involved in the atomic mass.
Third and fourth choices . . . both false; sadly, Joan is woefully unclear on the concepts.
Answer:
Explanation:
A simple light microscope uses light for imaging of objects where as a transmission electron microscope uses a monochromatic beam of electrons.
This beam is passed by a magnetic field which is very strong and thus act as a lens.
Its resolution of very high which is about 0.2 nanometers because of the separation between two atoms.
Because of this reason its resolution is about 1000 times greater than light microscope.
Answer:
A) vertically upward
Explanation:
Since the tyre is rotating with uniform angular speed and moving with constant linear speed
So as soon as a small stone is stuck into the groove of the tyre the speed of the stone is same as that of the tyre
so now we can say that stone will start revolving with the tyre of the car at constant angular speed and moving with uniform speed also
so here just after that the tangential acceleration of the stone must be zero while radial acceleration must be towards the center of the tyre given as

so we will have direction of net acceleration is towards its center so correct answer will be
A) vertically upward
The final answer is B hope its helps
Answer:
V = 2.5 J/C
Explanation:
<u><em>Given:</em></u>
Energy = E = 20 J
Charge = Q = 8 C
<u><em>Required:</em></u>
Potential Difference = V = ?
<u><em>Formula:</em></u>
V = 
<u><em>Solution:</em></u>
V = 20/8
V = 2.5 J/C