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:
This is a displacement vector since it is defined in terms of distance (meters, to be exact). The way you find the y-component is
which says that you multiply the magnitude of the vector (its length) by the sin of the direction (the angle):
and get
12.1 m
To
solve this problem, we assume that the wavelength of the light in air is 500
nanometers.
For this case we
only need the refractive index of the polystyrene. For an antireflective
coating, we need a quarter of wave thickness at the wavelength in the air. Which
means that the antireflective coating needs to be as thick as 1/4 of the
wavelength, divided by the coating’s refractive index. This is expressed
mathematically in the form:
x = λ / (4 * n)
where,
x = thickness
λ = wavelength
of light
n = index of
refraction of polystyrene
Substituting:
x = 500 nm / (4
* 1.49)
x = 500 nm / 5.96
x = 83.90 nm
I don't think so.
Before I can accept that rumor, I'll need to see the signed testimony of
two reputable adult witnesses, who have no connection to any business
that profits in any way from the production, sale, or consumption of food,
and who will swear in a public meeting, presided over by three respected
members of their community, that they personally saw more than one of
the alleged beakless double-breasted chickens in the same place at the
same time.
A photo is not acceptable ... not for me, and not for the two witnesses.
