Question

PLEASE ANSWER ALL QUESTIONS AND EXPLAIN

1.)  The nucleus of an atom has 95 protons and there are several isotopes that exist in equal amounts; which is true

   a. there must be 95 neutrons

   b. the atomic mass is 95

   c. the molar mass must be 190g/mol

   d. each isotope has a different number of neutrons

2) What does "X" represent in the following atomic symbol?

  

A) mercury (Hg)

B) chlorine (Cl)

C) scandium (Sc)

D) bromine (Br)

E) selenium (Se)

3) Determine the number of protons, neutrons and electrons in the following:

A) p+ = 18       n° = 18       e- = 22

B) p+ = 18       n° = 22       e- = 18

C) p+ = 22       n° = 18       e- = 18

D) p+ = 18       n° = 22       e- = 40

E) p+ = 40    n° = 22       e- = 18

Answer 1

1)

a) An isotope of an atom need not have equal number of neutrons and protons

i.e. An isotope of carbon has 7 neutrons, and 6 protons

b) Atomic mass of an atom is equal to total mass to protons and neutrons

c) The molar mass is equal to given mass of isotope divided by moles

d) Each isotope can have different number of neutrons

Hence the answer is d)

2) Halogens are represented by X in the periodic table

so the answer are B) and D)

3) No element given to determine number of protons, electrons and neutrons