Question

name: date: what is the charge of the nucleus of every atom? why is an atom electrically neutral? what does the atomic number of each atom represent? what is the difference between the mass number and the atomic number of an atom? atomic # mass # # of p⁺ # of n⁰ # of e⁻ symbol 9 10 14 15 47 25 55 25 what data must you know about the isotopes of an element to calculate the atomic mass of the element?

Explanation:

1. The nucleus of every atom has a positive charge because it contains protons which are positively - charged particles.
2. An atom is electrically neutral because the number of positively - charged protons in the nucleus is equal to the number of negatively - charged electrons outside the nucleus.
3. The atomic number of each atom represents the number of protons in the nucleus of the atom.
4. The mass number is the sum of protons and neutrons in the nucleus, while the atomic number is the number of protons. So the difference between the mass number and the atomic number of an atom is the number of neutrons.
5. To calculate the atomic mass of an element from its isotopes, you need to know the relative abundance and the mass of each isotope.

For the table:

• For the first row with atomic number 9:
• The number of protons ($p^+$) is equal to the atomic number, so # of $p^+$ = 9.
• Given # of $n^0$ = 10, mass number = # of $p^+$+# of $n^0$ = 9 + 10=19.
• In a neutral atom, # of $e^-$ = # of $p^+$ = 9. The element with atomic number 9 is Fluorine, symbol F.
• For the second row with # of $p^+$ = 14 and # of $n^0$ = 15:
• Atomic number = # of $p^+$ = 14.
• Mass number = # of $p^+$+# of $n^0$ = 14 + 15 = 29.
• # of $e^-$ = # of $p^+$ = 14. The element with atomic number 14 is Silicon, symbol Si.
• For the third row with mass number 47 and # of $n^0$ = 25:
• # of $p^+$ = Mass number - # of $n^0$ = 47 - 25 = 22.
• Atomic number = # of $p^+$ = 22.
• # of $e^-$ = # of $p^+$ = 22. The element with atomic number 22 is Titanium, symbol Ti.
• For the fourth row with mass number 55 and # of $p^+$ = 25:
• Atomic number = # of $p^+$ = 25.
• # of $n^0$ = Mass number - # of $p^+$ = 55 - 25 = 30.
• # of $e^-$ = # of $p^+$ = 25. The element with atomic number 25 is Manganese, symbol Mn.

Answer:

1. Positive charge.
2. The number of protons equals the number of electrons.
3. The number of protons in the nucleus.
4. The number of neutrons.
5. The relative abundance and mass of each isotope.

Table:

Atomic #	Mass #	# of $p^+$	# of $n^0$	# of $e^-$	Symbol
14	29	14	15	14	Si
22	47	22	25	22	Ti
25	55	25	30	25	Mn