You always start with metal (left side of the table) and then add non metal (right side) like NaCl
if there is more than one atom then you should mention that too. so in N2O3 you say di for 2 and then Nitrogen and tri for 3 oxygen
<em>In the late 1800's, experiments using cathode ray tubes led to the discovery of the;</em>
Electron(s)
<u>It was founded that many different metals release cathode rays, and that cathode rays were made of electrons, very small negatively charged particles.</u>
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:
B) 101,025
Explanation:
1000g * 0.449 J/g Celsius * 225 Celsius = 101,025
I got 225C from 250C - 25C
Ra, would have the lowest ionization energy. Remember ionization energy increases going up and to the right.