Alkali metals
Hydrogen only needs one more valence electron to fill it's out shell. So it belongs with the alkali metals.
I believe the most harmful substance would be element C, this is because element C has a very long half life therefore it has a very slow rate of a decay. Half life of a substance it the time taken for substance to decay to half its original mass or amount.
<span>Using proportions,
if x is the unknown volume we have:
1.84 / 1 = 42.5 / x </span>
<span>
Multiply both sides above by x:
1.84*x / 1 = 42.5
1.84*x = 42.5
Divide both sides by 1.84:
x = 42.5 / 1.84</span>
<span>X = 23.10 mL</span>
The objects may exchange heat between each other if they are in contact with each other.
The two objects will allow flow of heat between them if they have a difference in temperature from each other.
The heat will flow from higher temperature object to lower temperature object. The will reach a final temperature (common to each other) and then there will be no heat transfer between each other.
Answer:
The question 7 answer is false
the question 8 answer is true