So, here you have to look at the periodic table and see what the molar mass of each molecule composing the water compound

its two hydrogen atom plus an oxygen molecule, making it about 18g per mol.
That said, looking at the mass, we have to ask ourselves, if a mol of water contains 18g of mass, how many moles do we have in 0.5g of water?
We just do a cross multiplication:
Answer:
Step-by-step explanation:
If you're looking for what the half angle of the tangent of theta is, I'm a bit confused as to why you think the angle in the 4th quadrant, x, is relevant. But maybe you don't know it isn't and it's a "trick" to throw you off. Hmm...
Anyways, the half angle identity for tangent is

There are actually 3 identities for the tangent of a half angle, but this one works just as well as either of the others do, so I'm going with this one.
If theta is in QIII, the value of -4 goes along the x axis and the hypotenuse is 5. That makes the missing side, by Pythagorean's Theorem, -3. Filling in our formula:
which simplifies a bit to
and a bit more to

Bring up the lower fraction and flip it to divide to get
which of course simplifies to
-3. Choice A.
What is the equation of the line that best fits the given data? A graph has points (1, 7), (1, 6), (2, 5), (2.5, 5), (3, 3), (4,
Mice21 [21]
answer is d
Step-by-step explanation:
hope it is helpful
Answer:
7 people
Step-by-step explanation:
13-4=9
9+2=11
11-6=5
12-5=7