The boron group, carbon group, nitrogen group, oxygen group, halogens and noble gases are a part of which block of elements?
a. s- block
c. p- block
b. d- block
d. f- block

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

The sun generates both mechanical and electromagnetic waves. which statement about those wave is true?

Which wave is the result of amplification and produces a louder sound