Everything Science Grade 10

4.5 CHAPTER 4. THE ATOM

4. Which of the following are isotopes of U- 235? (E represents an element

symbol)

a.^23892 E

b.^23890 E

c.^23592 E

5. Complete the table below:

Isotope Z A Protons Neutrons Electrons

Carbon- 12

Carbon- 14

Iron- 54

Iron- 56

Iron- 57

6. If a sample contains 19 ,9%boron- 10 and 80 ,1%boron- 11 , calculate the

relative atomic mass of an atom of boron in that sample.

7. If a sample contains79%Mg- 24 ,10%Mg- 25 and11%Mg- 26 , calculate

the relative atomic mass of an atom of magnesium in that sample.

8. For the element^23492 U (uranium), use standard notation to describe:

a. the isotope with 2 fewer neutrons

b. the isotope with 4 more neutrons

9. Which of the following are isotopes of^4020 Ca?

a.^4019 K

b.^4220 Ca

c.^4018 Ar

10. For the sulphur isotope^3316 S, give the number of:

a. protons

b. nucleons

c. electrons

d. neutrons

More practice video solutions or help at http://www.everythingscience.co.za

(1.) 000x (2.) 000y (3.) 000z (4.) 0010 (5.) 0011 (6.) 0012

(7.) 0013 (8.) 0014 (9.) 0015 (10.) 0016

78 Chemistry: Matter and Materials