# Elemental and Forces Physics Questions

1. What is the quantum of light called?

a. the amplitude

b. the frequency

c. a photon

d. the wavelength

2. What is the oxidation number CHANGE for the iron atom in the reaction:

2 Fe2O3(s) + 3 C(s) --> 4 Fe(s) + 3 Co2(g)?

a. -6

b. -3

c. +3

d. +6

3. Of the following, which element has the highest first ionization energy?

a. aluminum

b. magnesium

c. silicon

d. sodium

4. The reaction of Cu(s) + 2 AgNO3(aq) --> Cu(NO3)2(aq) + 2 Ag(s) is best classified as a(n)

a. acid-base neutralization reaction

b. double replacement reaction

c. oxidation-reduction reaction

d. precipitation reaction

5. The average osmotic pressure of blood is about 7atm. Therefore,

a. the average blood pressure is about 7atm

b. the average pressure inside the body is about 7 atm above the external pressure.

c. a pressure of about 7atm would be required to prevent osmosis of blood is in contact with pure water across a semipermeable membrane.

d. all of the above

6. What is the smallest bond angle of SF6?

a. 60 degrees

b. 90 degrees

c. 109.5 degrees

d. 120 degrees

7. Calculate the work, w, done on the surroundings when a gas expands from 15L to 35L against a constant external pressure of 1.5atm. [1L.= 101J]

a. -5.3kJ

b. -3.0kJ

c. +3.0kJ

d. +5.3kJ

8. How many significant figures are there in the answer for the following problem?

57.5 + 0.9933 32 = ?

a. one

b. two

c. three

d. four

9. Which element has the highest first electron affinity?

a. B

b. C

c. Li

d. N

10. Which of the intermolecular forces is the most important contributor to the high surface tension shown by water?

a. dipole-dipole forces

b. dispersion forces

c. hydrogen bonding

d. ion-dipole forces

https://brainmass.com/chemistry/modern-quantum-theory/elemental-forces-physics-questions-170065

#### Solution Preview

1. What is the quantum of light called?

c. a photon

2. What is the oxidation number CHANGE for the iron atom in the reaction:

2 Fe2O3(s) + 3 C(s) --> 4 Fe(s) + 3 CO2(g)?

If we look at Fe2O3, we see that the Fe is at +3. How do we know that? We know because the oxygens are in an oxide which are -2 charge each. Therefore, since there are three of them, the total charge is -6. Therefore, we must have +6 with the irons. Since there are two irons, each must be at oxidation state of +3. Next, we know that elemental iron (like all atoms in their elemental form) is at oxidation state of 0. Therefore, the change goes from +3 to 0 which is a change of -3.

b. -3

3. Of the following, which element ...

#### Solution Summary

10 multiple choice questions on intermolecular forces, light, etc. are answered.

Particle Physics: Nuclear Force, Bohr, & Subatomic Particles

1. Considering Yukawa's hypothesis that the nuclear force should be due to the exchange of massive particles (that he called mesons), calculate the expected mass of this hypothetical meson.

2. Draw a table showing all the elementary spins 1/2 anti-particles arranged in three families horizontally with the individual members of each family vertically. In the table give the names, symbols, electric charges and approximate masses of each anti-particle.

3. In a unit system where c=h=1, the Compton wavelength for an muon is given by ___ (see attachment)___ calculate the numerical value. In the same system, the Bohr radius of a muonic hydrogen atom is given by (see attachment) where alpha is the fine structure constant alpha = 1/137, calculate the numerical value. [A muonic hydrogen atom is just equivalent to a regular hydrogen atom but the electron is substituted by a muon].

4. The weak interaction is assumed to be due to W or Z exchange. If the Z has a mass of 90 GeV/c^2, calculate the range of the weak interactions. How does this compare with the size of a nucleon

? What are the consequences for the likelihood of nuclear beta decay.

5. Two protons are separated by a distance of 10^-15m. Calculate (a) the electric force and (b) the gravitational force on one proton due to the other. Using the relative strengths of the strong, electromagnetic, weak and gravitational forces, estimate (c) the strong force and (d) the weak force between the two protons.

Summarize the four results in order of increasing strength.

View Full Posting Details