Answer:
I cannot give you all the answer but I can help you to solve those.
Explanation:
The first question:
How many grams are there in 7.5×
molecules of 
?
So we need to find the molecular mass first, use your periodic table,
And then we can find out 2+32+16×4=98 g/mol
Then, we need to find how many moles, by using Avogadro's constant:
Avogadro's constant: 1 mole = 6.02×
∴
=1.25 mol(2d.p.)
Lastly, find the grams using the formula 
m=Mn
m=1.25*98
m=122.5g
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In conclusion, use those formula to help you:
(which M = molecular mass(atomic mass) m=mass of the substance and n = moles)
Avogadro's constant: 
Answer:
D
Explanation:
Because the atomic number is 8, we can see that it is indeed an isotope of oxygen. If the mass number is 18, this means that the protons and neutrons added together = 18, so there are 10 neutrons. It does not have an atomic mass of 15.9994 like the element on the periodic table, however, as this is a confirmed isotope and not an average.
The x axis. This is because the numbers go on the side so the years have to go on the bottem
Answer:
I think it's C or D Sorry if I'm Wrong
Explanation:
it just makes the most sense to me
Answer:
The correct answer is - the uterus.
Explanation:
The uterus or the womb is an organ that appears to be pear-shaped and it is hollow from inside where the fetus is developed and it is also called the birth canal. The uterus has two parts one is the cervix and the other is the corpus.
The cervix makes the lower part of the uterus and opens up into the vagina the external reproductive organ of the females. The corpus is the part that makes the main body of the uterus. The uterus is present between the bladder and rectum where the egg fertilized and implanted itself.
