Answer:
All of the given statements are true.
Explanation:
All the elements are heavier than Bismuth (Bi) are radioactive.
The time for half of the original sample to spontaneous decay is called half life (
)

All radioactive elements are spontaneously decaying towards formation of a stable element.
Radioactive elements undergo decay in order to attain stability.
Radioactivity is a natural part of our environment. The earth also contains several primordial long-lived radioisotopes that have survived to the present in significant amounts.
Hence, all the given statements are true.
Answer:- Third choice is correct, 17.6 moles
Solution:- The given balanced equation is:
Al_2(SO_4)_3+6KOH\rightarrow 2Al(OH)_3+3K_2SO_4
We are asked to calculate the moles of potassium hydroxide needed to completely react with 2.94 moles of aluminium sulfate.
From the balanced equation, there is 1:6 mol ratio between aluminium sulfate and potassium hydroxide.
It is a simple mole to mole conversion problem. We solve it using dimensional set up as:
2.94molAl_2(SO_4)_3(\frac{6molKOH}{1molAl_2(SO_4)_3})
= 17.6 mol KOH
So, Third choice is correct, 17.6 moles of potassium hydroxide are required to react with 2.94 moles of aluminium sulfate.
your answer will be :
B. <u>Na has a lower</u> <u>electronegativity than H</u>
because Na belongs to alkali metals which are least electronegative (most electro positive) but hydrogen is a non metal, it has higher electronegativity as compared to metals like Sodium (Na).
Answer:
the error could have been the fact that the unit for volume wasn't changed from cm³ to dm³
hence the calculation error
the solution to this would be first dividing the volume by 1000 to get that same amount in dm³ which is the standard unit to be used for volume-density calculations