251. Vitamin B is soluble in
(A) Water
(B) Fats
(C) Both A & B
(D) None of these

252. The atomic number of an element is the number of _____ in the _____ of an atom.
(A) electrons, first shell
(B) electrons, last shell
(C) neutrons, nucleus
(D) protons, nucleus

253. An element is a substance whose atoms all have the same
(A) neutrons
(B) electrons
(C) atomic number
(D) mass number

254. The atomic number of Hydrogen is
(A) 1
(B) 2
(C) 8
(D) 16

255. Electron in its ground state does not
(A) spin
(B) revolve
(C) reside in orbit
(D) radiate energy

256. The number of periods in modern periodic table is
(A) 5
(B) 6
(C) 7
(D) 8

257. Which of the following is a transition element?
(A) Cu
(B) Cl
(C) S
(D) B

258. Ink spreads in water because of
(A) Vapor pressure
(B) Diffusion
(C) Dipole movement
(D) Osmosis

259. The pH of a neutral solution is
(A) 5
(B) 7
(C) 10
(D) 14

260. The pH of an acidic solution is _____ 7.
(A) less than
(B) greater than
(C) equal to
(D) (A) and (C)