Chapter 3

Give the number of outer (valence) electrons for an atom of sodium.

1

To draw a Lewis structure, first add the number of outer (valence) electrons contributed by each atom to obtain the total number of outer electrons. What is this value for a molecule of O2?

12

To draw a Lewis structure, first add the number of outer (valence) electrons contributed by each atom to obtain the total number of outer electrons. What is this value for a molecule of H3COH?

14

Give the number of protons, neutrons, and electrons in a neutral atom represented by 65/29CU

36 neutrons 29 protons 29 electrons

Use the figure below to specify the region of the electromagnetic spectrum where radiation with a wavelength of 700 cm is found.

700 cm*(1/10^2)= 7x10^0 Radio region 10^9= nm

How much energy is associated with an infrared photon with a wavelength of 7.50 μm

E= hc/λ E= (6.63 × 10^−34)(3.00 × 10^8)/(7.50 μm)(1/10^6) =2.65×10−20 J

Place types of electromagnetic radiation listed below in order from shortest wavelength to longest wavelength.

Gamma, xrays, UV-Visible, infrared, microwave, radio

Place types of electromagnetic radiation listed below in order from lowest energy to highest energy.

Radio, microwave, infrared, UV-Visible, xrays, gamma

Which photons have more energy, those in the infrared or the visible region of the electromagnetic spectrum?

Visible

Calculate the wavelength of a photon of electromagnetic radiation with a frequency of 51 MHz.

λ = c/v (3.00 × 10^8/5.1 × 10^7)= 5.88 m