B because A is the experiment so you won't have the data until after, not C because that's when you have your final verdict on the experiment not just looking at results, and not D because a hypothesis is something you form before an experiment. Hope this helped!<span />
The low-mass elements, hydrogen and helium, were produced in the hot, dense conditions of the birth of the universe itself. The birth, life, and death of a star is described in terms of nuclear reactions. The chemical elements that make up the matter we observe throughout the universe were created in these reactions.
Answer:
All of these three are polar molecules or ions
Explanation:
1) CO3 ^2-
It is a polar ion because it consists of one Oxygen atom and three carbon atoms so there is a substantial electroegativity difference between carbon and Oxygen due to which shared electrons are attracted more towards Oxygen creating partial negative charge on it and less towards carbon creating a partial positive charge on it, which makes the overall ion polar.
2) HCN
HCN is a polar molecule because there is substantial electronegativity difference between Carbon and Hydrogen as well as between Carbon and Nitrogen. Due to this negative charge is induced over Nitrogen because electronegativity of Nitrogen is 3.0 and positive charge on Carbon because its electronegativity is 2.5. The overall molecule is polar.
3) NO3^-1
Nitrate ion is also a polar molecule because there are three atoms of Oxygen and one atom of Nitrogen. There is substantial electronegativity difference between oxygen (3.44) and nitrogen (3.0) due to which partial positive charge is created on Nitrogen and partial negative charge created over three Oxygen atoms. The overall molecule is polar.
Hope it helps!
