ws 3 isotopes at wt names

GenChem Worksheet 3

1. How many neutrons, protons, and electrons are in the following species?

a.

235

U ______ p ______ n _______ e

b. copper-63 ______ p ______ n _______ e

2. Which atom has the same number of neutrons as 52Cr?

a. 50Fe b. 52Fe c. 56Fe d. 54Fe e. 59Fe

3. Find the element, chlorine in the periodic table. What is the number of protons and electrons in this element?What is the atomic number? What is the atomic weight?

4. What is X in the isotope symbol

614

X?

5. Identify the element X for the following ions: (a) X2+ with 36 electrons (b) X- with 36 electrons

6. List all the elements that have chemical properties similar to those of boron?

7. Naturally occuring copper consists of two stable isotopes that contribute to the average atomic weight of copper. One isotope is copper-63, which accounts for 69.17 % of the total amount of naturally occurring copper and has a mass of 62.94. Calculate the atomic mass of the other naturally occurring isotope.

8. Predict the type of bonds that would form between the following elements in a compound.a. B and Br ___________ b. Na and S___________ c. H and I ___________ d. Mg and N _____________

9. Elements gain or lose electrons to form ions. Write the word "gain" or "lose" electrons by each symbol, the number of electrons, and the ion symbol.

EX. Al loses 3 e- to form Al3+

a. N ______ _____ e- to form ____ b. O ______ _____ e- to form ______c. Ca ______ _____ e- to form ______ d. Cs ______ _____ e- to form ______e. Br ______ _____ e- to form ______ e. __ ______ _____ e- to form Ni2+

10. Name these ions formed from their elements

a. Fe3+ b. Br- c. Te2- d. P3- e. Sr2+ f. S2-

11. How many neutrons, protons, and electrons are in the following species?

a.

2759

Co 3+ ______ p ______ n _______ e

b.

128

Te 2- ______ p ______ n _______ e

12. How many protons and electrons does the U3+ ion have?

13. Element X reacts with element Y to give a product containing X3+ ions and Y2- ions.a. Is element X a metal, metalloid, or nonmetal?b. Is element Y a metal, metalloid, or nonmetal?c. What is the formula of the product compound?d. What main groups of the periodic table are elements X and Y likely to be found in?

Answers 1. How many neutrons, protons, and electrons are in the following species?

a.

235

U ___92___ p ___143___ n ____92___ e

b. copper-63 ___29___ p ____34__ n ____29___ e

2. Which atom has the same number of neutrons as 52Cr? d. 54Fe

a. 50Fe b. 52Fe c. 56Fe d. 54Fe e. 59Fe

3. Find the element, chlorine in the periodic table. What is the number of protons and electrons in this element? (17 p and 17 e) What is the atomic number? (17) What is the atomic weight? (35.45)

4. What is X in the isotope symbol

614

X? X = C

5. Identify the element X for the following ions: (a) X2+ with 36 electrons (X = Sr) (b) X- with 36 electrons (X = Br)

6. List all the elements that have chemical properties similar to those of boron? Elements must be in group 3A: B, Al, etc.

7. Naturally occurring copper consists of two stable isotopes that contribute to the average atomic weight of copper. One isotope is copper-63, which accounts for 69.17 % of the total amount of naturally occurring copper and has a mass of 62.94. Calculate the atomic mass of the other naturally occurring isotope.

0.6917 x 62.94 + 0.3083y = 63.55 y = 64.92

8. Predict the type of bonds that would form between the following elements in a compound.a. B and Br = covalent b. Na and H = ionic c. H and I = covalent d. Mg and N = ionic

9. Elements gain or lose electrons to form ions. Write the word "gain" or "lose" electrons by each symbol, the number of electrons, and the ion symbol.

EX. Al loses 3 e- to form Al3+

a. N gains 3 e- to form N3- b. O gains 2e- to form O2-

c. Ca loses 2 e- to form Ca2= d. Cs loses 1 e- to form Cs+

e. Br gains 1 e- to form Br- e. Ni loses 2 e- to form Ni2+

10. Name these ions formed from their elements

a. Fe3+ = iron (III) ion b. Br- = bromide ion c. Te2- = telluride ion d. P3- = phosphide ione. Sr2+ = strontium ion f. S2+ = sulfide ion

11. How many neutrons, protons, and electrons are in the following species?

a.

2759

Co 3+ ___27___ p ___32___ n ___24____ e

b.

128

Te 2- ___52___ p ___76___ n ___54____ e

12. How many protons and electrons does the U3+ ion have? 92 p and 89 e

13. Element X reacts with element Y to give a product containing X3+ ions and Y2- ions.a. Is element X a metal, metalloid, or nonmetal? X = metalb. Is element Y a metal, metalloid, or nonmetal? Y = nonmetalc. What is the formula of the product compound? X2Y3

d. What main groups of the periodic table are elements X and Y likely to be found in? X = 3A and Y = 6A