For #1, I'd say it's "It will usually bond to multiple atoms which can provide a total of 4 additional electrons."
2. Ionic (I'm quite certain because anions/cations (-1 & +1) are Ionic from what I recall, if that's true it's Ionic.
3. "comparison of the associated families to which the elements belong" and
"the difference in electronegativities" are what I would choose, as I mentioned in a comment earlier.
If I'm wrong let me know, but I am at least 80% sure that these responses are correct from what I remember in Chemistry.
Answer : The
must be administered.
Solution :
As we are given that a vial containing radioactive selenium-75 has an activity of
.
As, 3.0 mCi radioactive selenium-75 present in 1 ml
So, 2.6 mCi radioactive selenium-75 present in 
Conversion :

Therefore, the
must be administered.
Answer:
Double replacement reaction
Explanation:
Now, let us first write the reaction equation properly:
H₂SO₄ + 2KOH ⇒ K₂SO₄ + 2H₂O
The above reaction is a neutralization reaction between an acid and a base whose product gives salt and water only at most instances.
From here, we can observe that the species displaces on another in their ionic state. Hydrogen replaces potassium and water is produced. Potassium combines chemically with sulfate ions to give the salt of potassium.
Answer:
c) No, because Celsius is not an absolute temperature scale
Explanation:
converting 5 oC to kelvin which is the absolute temperature scale gives = 273 + 5 = 278 K
and converting 20 oC to kelvin = 20 + 273 = 293 K
the ratio = 278 / 293 = 0.94 approx 1 not 4