Question

identify the choice that best completes the statement or answers the question. 1. what is the atomic number for nickel? a. 58 b. 58.693 c. 28 d. 7 2. a neutral atom of sulfur contains a. 16 electrons b. 32.066 electrons c. 14 electrons d. 32 electrons 3. the atomic mass of an element depends upon the a. mass of each electron in that element b. mass of each isotope of that element c. relative abundance of protons in that element d. mass and relative abundance of each isotope of that element 4. what does the number 88 in the name strontium - 88 represent? a. the atomic number b. the mass number c. the sum of the protons and electrons d. twice the number of protons 5. to what element does polonium - 208 (atomic number 84) decay when it gives off an alpha particle? a. ²¹⁰pb b. ²¹⁰po c. ²⁰⁴pb d. ²⁰⁸rn 6. the behavior of cathode rays produced in a glass tube containing gas led j.j. thomson to conclude that the rays a. were not composed of matter b. were composed of negatively charged particles c. were composed of positively charged particles d. were composed of uncharged particles 7. the mass number of an element whose atoms have 13 protons and 14 neutrons is a. 27 b. 13 c. 14 d. 1

Explanation:

Step1: Recall nickel's atomic number

Nickel's atomic number is 28. So for question 1, the answer is c.

Step2: Analyze sulfur atom

A neutral sulfur atom has 16 protons and 16 electrons. So for question 2, the answer is a.

Step3: Understand atomic mass concept

The atomic mass of an element depends on the mass and relative abundance of each isotope of that element. So for question 3, the answer is d.

Step4: Know about mass - number

The number 88 in strontium - 88 represents the mass number. So for question 4, the answer is b.

Step5: Analyze alpha - decay

When polonium - 208 (atomic number 84) gives off an alpha particle (helium nucleus with 2 protons and 2 neutrons), the new element has atomic number 82 and mass number 204, which is lead - 204 ($^{204}_{82}Pb$). So for question 5, the answer is c.

Step6: Recall Thomson's experiment

J.J. Thomson concluded that cathode rays were composed of negatively charged particles. So for question 6, the answer is b.

Step7: Calculate mass number

The mass number is the sum of protons and neutrons. For an atom with 13 protons and 14 neutrons, the mass number is 13 + 14=27. So for question 7, the answer is a.

Answer:

1. c. 28
2. a. 16 electrons
3. d. Mass and relative abundance of each isotope of that element
4. b. the mass number
5. c. $^{204}_{82}Pb$
6. b. were composed of negatively charged particles
7. a. 27