1. Naturally occurring neon has average atomic mass of 20.18 amu and has two naturally occurring isotopes: :°Ne. 19.99 amw 'Ne. 21.99 amu. The percent abundances of the neon isotopes are _______% ²⁰Ne and _____%²²Ne.

A) 20.22 B) 4.5, 95.5 C) 95.5, 4.5 D) 90.5. 9.5 E) 9.5. 90.5

2. Magnesium and sulfur form an ionic compound with the formula A) NlgS: B) C) MgS I)) MO; EI Nig2S

3. Which of the following correctly lists the five atoms in order of increasing size? A)FD)F

4. Which ion below has the largest radius?

A) Cl' B) K⁺ C) Br^- D) F^- E) Na⁺

5. The value of ΔH^o for the reaction below is -72 ___kJ of heat are released when 80.9 grams of HBr is formed in this reaction.

H₂ (g) + Br₂(g) → 2HI3r(g)

A) 144 B) 72 C) 0.44 D) 36 E) -72

6. A sample of aluminum metal absorbs 11.2 1 of heat. upon which the temperature of the sample increases from 23.2 t to 30.5 °C. Since the specific heat capacity of aluminum is 0 901 'g-K, the mass of the sample is g

A) 72 B) 1.7 0 10. 0)65 EI 7.3

7. Based on observed periodic trends. arrange the following species. tffir,11C1. III. 111. in order of increasing dipole moment.

A) HF < HCI < HBr < HI B)HBr < HCI < HE < HI C)Hl < HF < HCI < HBr

D) HI < HBr < HCI < HF E)HCI < HBr < HI < HF

8. Label the hybridization at C#1, C#2, C#3. and C#4 in the molecule.

              0 H
               | | 
H-C ≡ C-C-C-H
    1     2  3 | 4

                  H

    C1 C2 C3 C4

A) sp sp sp³ sp³d

B) sp sp sp² sp³

C) sp sp² sp² sp²

D) sp² sp² sp³ sp³

E) sp³ sp³ sp³ sp³

9. What is the energy of a mole of photons associated with light of viavelength 930 nm?

10. How many significant figure should be used in reporting the answers to the following:

a) 103 + 910.15

b) 0.0120 x 10¹⁰ / 1(100.50)(1.01139)1

11. The energy required for an electronic transition in a Rohr hydrogen atom from n = 2 to n = 3 is--------J.

12. Given the data in the table below, Calculate ΔH^o_rxn in kJ for the reaction. Show your work.

3NO₂ +H₂0(I) -> 2HNO₃(aq)+NO(g)

Substance  ΔH_f (kj/mol)

H₂0 (1)         -286

NO (g)            90

NO₂ (8)           24

HNO₃ (4:0 -207

t4H₃ (g) -46