practicequiz06 - Practice Quiz, Ch. 2 Chemistry of Life...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Practice Quiz, Ch. 2 Chemistry of Life (rev 7/07) 1) About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter? A) oxygen, hydrogen, calcium, sodium B) carbon, oxygen, sulfur, calcium C) carbon, hydrogen, nitrogen, oxygen D) carbon, sodium, chlorine, nitrogen E) carbon, sulfur, phosphorus, hydrogen 2) Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates? A) iodine B) nitrogen C) phosphorus D) calcium E) sodium 3) Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atom's nucleus? A) atomic weight B) atomic number C) atomic mass D) mass number E) mass weight 4) How do isotopes of the same element differ from each other? A) amount of radioactivity B) number of electrons C) number of neutrons D) number of protons E) valence electron distribution 5) One difference between carbon-12 and carbon-14 is that carbon-14 has A) two more protons than carbon-12. B) two more neutrons than carbon-12.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

practicequiz06 - Practice Quiz, Ch. 2 Chemistry of Life...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online