51) The most abundant elements, in terms of atom percent, in the human body are ________.
A) carbon and oxygen
B) oxygen and hydrogen
C) hydrogen and carbon
D) nitrogen and carbon
52) In which of the following sequences of elements does each of the elements have a one-letter
symbol?
A) sulfur, vanadium, cobalt
B) chlorine, iron, lithium
C) nickel, yttrium, potassium
D) hydrogen, fluorine, phosphorous
53) In which of the following sequences of elements does each of the elements have a two-letter
symbol?
A) sodium, lithium, iodine
B) potassium, fluorine, carbon
C) tin, hydrogen, iodine
D) silicon, chlorine, chromium
54) In which of the following sequences of elements does each of the elements have a symbol
which starts with a letter that is not the first letter of the element’s English name?
A) silver, gold, mercury
B) copper, helium, neon
C) cobalt, chromium, sodium
D) argon, iron, lead