SAT Subject Test Chemistry,10 edition

(A) 35  neutrons,   35  protons,    34  electrons

(B) 40  neutrons,   40  protons,    39  electrons

(C) 40  neutrons,   35  protons,    34  electrons

(D) 37  neutrons,   38  protons,    39  electrons

(E) 40  neutrons,   35  protons,    35  electrons

47 . A physicist starts out with 320 grams of a radioactive element Z and after 20 minutes he
has only 20 grams left. What is the half-life of element Z?

(A) 2   minutes

(B) 3   minutes

(C) 4   minutes

(D) 5   minutes

(E) 10  minutes

48 . The modern periodic table is ordered on the basis of

(A) atomic  mass

(B) atomic  radius

(C) atomic  charge

(D) atomic  number

(E) number  of  neutrons

49 . A catalyst

(A) changes ∆G  for an  equation

(B) acts    by  increasing  the rate    of  the forward reaction    more    than    the reverse reaction

(C) raises  the equilibrium constant    of  a   system

(D) may have    a   molecular   weight  as  low as  1   or  higher  than    200,000

(E) does    not react   chemically  during  the course  of  a   reaction