<u>Answer:</u> The tendency of an element to react is closely related to the number of valence electrons in the element.
<u>Explanation:</u>
Chemical reactivity is defined as the tendency of an element to loose of gain electrons.
Metals tend to loose electrons and so their chemical reactivity is the tendency to loose electrons.
Non-metals tend to gain electrons and so their chemical reactivity is the tendency to gain electrons.
The number of electrons that an element will loose or gain depends on the number of valence electrons present around that element.
<u>For Example:</u> Chlorine has 7 valence electrons and need 1 electron to complete its octet, whereas sulfur has 6 valence electrons and need 2 electrons to complete its octet.
So, chlorine will gain 1 electron easily than sulfur and thus, is more reactive than sulfur.
Hence, the tendency of an element to react is closely related to the number of valence electrons in the element.
<span>Answer:
Enthalpy is delta-H-
We need to look at the molecule and determine which bonds are broken adn which bonds are formed.
Bonds that are broken are H-H (from the H2 molecule) and the C=O from acetone.
their energies add up like this: 436 kJ + 745 kJ = 1181 kJ
looking at the bonds formed, these are C-O, O-H, and C-H. these add up to 1229 kJ
solving for delta H by taking the sum of the broken bonds and subtracting the sum of the formed bonds, like so:
1181 - 1229 = -48 kJ</span>
The building blocks of protein are amino acids.
Amino acids are a class of organic compounds that contain at least one amino group, -NH2, and carboxyl group, -COOH.
Alpha amino acids , RCH(NH2)COOH, are the building blocks from which proteins are constructed.
The NH group of one amino acid and the COOH group of the other amino acid are joined together and a peptide bond -CONH- is formed between the two amino acids and the product is called a dipeptide.
<span>The ability of an atom to attract the shared electrons in a covalent bond is its:</span>electronegativity.