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1. Write symbols for each of the isotopes: a. Each atom contains one proton and

ID: 484127 • Letter: 1

Question

1. Write symbols for each of the isotopes:

a. Each atom contains one proton and two neutrons

b. Each atom contains 92 protons and 146 neutrons.

2. One element lithium has two naturally occurring isotopes. One of these has a mass of 6.0151amu and a natural abundance of 7.49%. A second isotope has a mass of 7.0160 amu and a natural abundance of 92.51%. Calculate the atomic mass of lithium.

3. For each of the elements Ca, K, Cu, Zn, Br and Kr, provide the following information:

a. Which are metals?                         ____________________

b. Which are representative metals?    ____________________

c. Which are inert or noble gases?       ____________________

Explanation / Answer

1. a] 1H

b] 238U

2.  Atomic mass = ( 6.0151 x 7.49) + ( 7.0160 x 92.51)/ 100

= 45.053 +649.050/100

= 694.103/100

= 6.94 amu

3. a] Metals are Ca,K,Cu,Zn

b] Represenatvive metals Br

c] Inert or noble gases Kr