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Q1. Copper was discovered with abundances of 69.97 % for 63Cu and 31.03 % for 65

ID: 1032649 • Letter: Q

Question

Q1. Copper was discovered with abundances of 69.97 % for 63Cu and 31.03 % for 65Cu. The mass of 63Cu is 62.9300 amu. The mass of 65Cu is 64.9200 amu. What is the atomic mass of copper? Q2. Write the symbolic notation of an isotope of an element having 8 protons, 8 electrons, and 9 neutrons. Q3. Arrange the following elements in order of decreasing atomic size; Al, Na, Cl, F, O Q4. The ion Zn2+ contains how many electrons? Q5. Which element has the electron configuration of Q6. What is the order of electronegativity of Ba, I, and Cl (least to highest)? Q7. The isotope Chromium has a half-life of 28 days. If the original sample had a mass of 28.0 grams, what mass of the Chromium-51 sample remains after 84 days? Q8. Complete the nuclear equation below; 98 43 Q9. What is the IUPAC name for Mg(NO3)2? Q10. What is the formula for the compound tin(I) fluoride? Q11. What is the name of the phase change when a liquid becomes a gas? Q12. CHCl3, CO, CO2, and NH3 Which one of the above is a nonpolar molecule?

Explanation / Answer

1)

Given:

m1 = 62.93 amu

A1 = 69.97 %

m2 = 64.92 amu

A2 = 31.03 %

use:

atomic mass = sum of (mass of isotope * abundance) / 100

m = (m1*A1 + m2*A2)/100

= (62.93*69.97 + 64.92*31.03)/100

= 64.176797 amu

Answer: 64.1768 amu

2)

Number of proton = 8

So, atomic number is 8

Atomic number is 8 for Oxygen

mass number = number of proton + number of electron

= 8+9

= 17

since number of proton and electrons is same, charge is 0

Answer:

178O

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