SUPER fast chemistry questions?!?

Question

1. Two atoms of the same element must have the same number of _____

A neutrons

B protons

C electrons

D neutrons plus protons

E protons plus electrons

2. Which of the following is not a characteristic that makes radioactive tracers useful in medical diagnoses?

A They are incorporated into reactions in living material.

B They are easily detectable in minute amounts.

C They may damage or destroy molecules.

D Living cells cannot distinguish them from nonradioactive isotopes.

E They can be used with PET scanners.

3. Which is not involved in, or is not relevant to, hydrogen bonding?

A attraction of electrons by one atom more than another

B partial electrical charges

C attraction between unlike partial charges

D loss of electrons

E polar molecules

Answer 1

1) B Protons

Protons determine the atomic number which determines the element.

2) C

Radioactive molecules are not harmful to other molecules. If they were harmful they would damage tissue. This would worsen a medical condition so it is not a characteristic of radioactive tracers.

3) D loss of electrons

Hydrogen bonding involves the attraction of unlike partial charges. When hydrogen bonds are formed no electrons are loss.

Answer 2

1 b  2 c   3 D

Answer 3

1. protons and electrons because the amount of protons is equal to the amount of electrons

2.C beause damaging or destroying any type of evidence is not useful

3. A because hydrogen doesn't attract others but fluorine on the other hand will because it's on the upper right hand corner of the periodic table of elements

Hope you get a good score!

Answer 4

1) B.  The number of protons defines each element.  The number of neutrons can vary, giving rise to elemental isotopes and the number of electrons can vary if the element is in an oxidized or reduced form (i.e. a charged salt form)

2) C.  I don't believe that the isotopes used as radioactive tracers are sufficiently "hot" to induce chemical reactions or decomposition to surrounding biomolecules.

3) D.  Hydrogen bonding is not a chemical reaction, but is more of a sharing of a proton between two regions of electron density.

Answer 5

1 b 2 c 3 D