An element has an atomic number of 15. With which of the following elements will it show similar chemical properties?
(A) Be (4)
(B) Ne (10)
(C) N (7)
(D) O (8)

An element's chemical properties are primarily determined by its atomic number, which is also equal to the number of protons in its nucleus. Elements with similar atomic numbers tend to have similar chemical properties because they have the same number of protons and, therefore, the same number of electrons in their outermost electron shells.

In this case, the element with an atomic number of 15 is phosphorus (P). To find elements with similar chemical properties, we can look for elements with nearby atomic numbers.

(A) Beryllium (Be) has an atomic number of 4.
(B) Neon (Ne) has an atomic number of 10.
(C) Nitrogen (N) has an atomic number of 7.
(D) Oxygen (O) has an atomic number of 8.

Out of the options provided, nitrogen (N) has the nearest atomic number to phosphorus (P), as both have atomic numbers that are relatively close to each other. Therefore, the element with an atomic number of 15 (phosphorus) will show similar chemical properties to the element with an atomic number of 7 (nitrogen), so the correct choice is (C) N(7).