Answer:
1. Alkali metals (group 1)
2. halogens (Group 17)
3. noble gasses (group 18)
Explanation:
1. alkali metals only have one valence electron meaning that they really want to lose that one valence electron to get a full octet.
2. halogens have 7 valence electrons meaning that they just need to gain 1 to get a full octet.
3. Nobel gasses already have a full octet meaning that they don't want to react. (atoms only react to get a full octet)
I hope this helps. Let me know if anything is unclear.
Don't all halogens have 8 valence electrons? They don't need to gain or lose any because they are already stable.
Answer:
1.54 moles of pure ethanol are present in 750mL of wine
Explanation:
The sort of concentration 12% by volume, means that in 100 mL of solution (wine) 12 mL are pure ethanol
We use the density of pure ethanol to determine the mass:
Ethanol density = Ethanol mass / Ethanol volume
Ethanol density . Ethanol volume = Ethanol mass
0.789 g/mL . 12 mL = 9.47 g of ethanol
Now we can determine the moles: 9.47 g . 1 mol / 46.06 g = 0.205 moles
Now we can make a rule of three:
In 100 mL of solution (wine) we have 0.205 moles of pure ethanol
Then, in 750 mL of solution we may have (750 mL . 0.205) / 100 = 1.54 moles
Answer:
a. Sn or Si ⇒ Sn
b. Br or Ga ⇒ Ga
c. Sn or Bi ⇒ similar in size
d. Se or Sn ⇒ Sn
Explanation:
The larger atom has a larger atomic radius. We have to consider how varies the atomic radius for chemical elements in the Periodic Table. In a group (column), the atomic radius increases from top to bottom while in a period (file), it increases from right to left.
a. Sn or Si ⇒ Sn
They are in the <u>same group</u>. Sn is on the top, so it has a larger atomic radius.
b. Br or Ga ⇒ Ga
They are in the <u>same period</u>. Ga is located at the left so it has a larger atomic radius.
c. Sn or Bi ⇒ similar
They are not in the same group neither the same period. Bi is located more at the bottom, so it would be larger than Sn, but Bi is also at the right side, so it would be smaller than Bi. Thus, they have comparable sizes.
d. Se or Sn⇒ Sn
They are not in the same group neither the same period. Se is located at the top and right side compared to Sn, so Sn is the larger atom.
Answer:
Cl2(g) + H2O <–> HOCl + H+ + Cl-
