hw 1 (atomic composition, isotopes, nomenclature, mole, light)

Question 1

An atom of the isotope ¹³³Cs contains how many protons (p), neutrons (n), and electrons (e)?

Answer 1

55 p, 78 n, 55 e

Question 2

What is the atomic symbol and mass number for an atom containing 50 protons and 64 neutrons?

Answer 2

¹¹⁴Sn

Question 3

Determine the number of protons (p) and electrons (e) in Mg²⁺.

Answer 3

12 p, 10 e

Question 4

An unknown element is a mixture of isotopes ¹²⁰X and ¹²²X. The average atomic mass of X is 121.47 amu. What is the percent abundance of ¹²²X?

Answer 4

73.5%

Question 5

Provide the correct IUPAC name for AlN.

Answer 5

aluminum nitride

Question 6

Provide the correct IUPAC name for CaBr₂.

Answer 6

calcium bromide

Question 7

Provide the correct IUPAC name for Mg₃(PO₄)₂?

Answer 7

magnesium phosphate

Question 8

Write the chemical formula for dichlorine heptoxide

Answer 8

Cl₂O₇

Question 9

Determine the correct formula for iron(III) perchlorate

Answer 9

Fe(ClO₄)₃

Question 10

If 5.3 kg of CO₂ are produced during a combustion reaction, how many molecules of CO₂ would be produced?

Answer 10

7.3 × 10²⁵ molecules

Question 11

Determine the number of molecules in 36.7 grams of NO₂

Answer 11

4.80 × 10²³ molecules

Question 12

How many atoms of He can a balloon that has a 21 cm diameter hold? The density of Helium is 1.18 g/L.
(Assume the balloon is a sphere).

Answer 12

8.6 × 10²³ atoms

Question 13

Which color (frequency) of light travels the fastest in a vacuum?

Answer 13

All have the same speed

Question 14

Define frequency as it relates to a electromagnetic wave.

Answer 14

Frequency is the number of wave cycles that pass a specified point in space in a specified amount of time

Question 15

Define wavelength as it relates to a electromagnetic wave.

Answer 15

Wavelength is the distance between two consecutive peaks or troughs in a wave

Question 16

Identify the region of the electromagnetic spectrum where the wavelength measurement of 7 μm can be found.

Answer 16

Infrared

Question 17

What is the frequency of green light that has a wavelength of 535 nm? (c = 3.00 x 10⁸ m/s)

Answer 17

5.61 × 10¹⁴ s⁻¹

Question 18

Provide the correct IUPAC name for Cu(ClO₂)₂

Answer 18

copper(II) chlorite