Answer:
b.) Br and Br
Explanation:
A covalent bond occurs when electrons are shared between two atoms causing them to form a bond.
A "pure" covalent bond refers to a nonpolar covalent bond. In these bonds, the electrons are shared equally between two atoms as a result of the absence of an (or very small) electronegativity difference. The purest covalent bond would therefore be between two atoms of the same electronegativity. Two bromines (Br) have the same electronegativity, thus making it the purest covalent bond.
Polar covalent bonds occur when electrons are shared unequally between two atoms. There is a larger electronegativity difference between the two atoms, but not large enough to classify the bonds as ionic. In this case, a.) and c.) are polar covalent bonds and d.) is an ionic bond.
Measuring the ratio of C-14 to C-12 in the remains of dead organisms to determine how much time has passed since the organism died
the answer is D
Here is the answer for the three of them
<span>N20 = 16 e-
</span><span>SeCl2 =20
</span><span>PBr3 = 26
Remember that t</span><span>o find the valence electrons in an atom you need to identify what group the element is in. An element in group 1A has 1 valence electron. If the element is in group 2A, then it has two valence electrons.</span>
<u>Answer:</u> The number of carbon and oxygen atoms in the given amount of carbon dioxide is
and
respectively
<u>Explanation:</u>
To calculate the number of moles, we use the equation:

Given mass of carbon dioxide gas = 3.45 g
Molar mass of carbon dioxide gas = 44 g/mol
Putting values in above equation, we get:

1 mole of carbon dioxide gas contains 1 mole of carbon and 2 moles of oxygen atoms.
According to mole concept:
1 mole of a compound contains
number of molecules
So, 0.0784 moles of carbon dioxide gas will contain
number of carbon atoms and
number of oxygen atoms
Hence, the number of carbon and oxygen atoms in the given amount of carbon dioxide is
and
respectively
Answer:
FALSE.
Explanation:
The right answer is false. There are three different groups of phylum for worms.
Hope this helped!