CHEMISTRY 130 ARIZONA COLLEGE OF NURSING MIDTERM CERTIFICATION EVALUATION EXAMS COMPLETE QUESTIONS AND ANSWERS PRACTICE SOLUTION

CHEMISTRY 130 ARIZONA COLLEGE OF
NURSING MIDTERM CERTIFICATION
EVALUATION EXAMS COMPLETE
QUESTIONS AND ANSWERS PRACTICE
SOLUTION

⩥ How many electrons does a neutral atom of Lithium have?
Answer: 3.0


⩥ How many electrons does a Calcium ion with a charge of +2 have?
Answer: 18.0


⩥ How many neutrons should Beryllium have with an atomic number of
4 and an atomic mass of 9 from the Periodic Table?
Answer: 5.0


⩥ How many neutrons should oxygen have based on its atomic number
(8) and atomic mass (16) on the periodic table?
Answer: 8.0


⩥ How many protons does sodium have?
Answer: 11

, ⩥ What is the average atomic mass (with four sig figs) of silicon given
the following abundance information on the isotopes of silicon?
Mass number Abundance
Si-28 92.21 %
Si-29 4.70 %
Si-30 3.09 %
Answer: 28.11


⩥ Neon has two isotopes: Ne-20 (having a mass of 20 ) and Ne-22
(having a mass of 22 ). Given the following abundances of these
isotopes in nature, what is the average atomic mass of neon with three
sig figs?
Mass number Abundance
Ne-20 90%
Ne-22 10%
Answer: 20.2


⩥ What is the name for an element that has different masses? Enter the
word only.
Answer: isotope


⩥ The name for NaF is