The Atom - Different Atoms

Question 1

atomic number

Answer 1

• number of protons and electrons

Question 2

silver

Answer 2

• atomic number: 47
• 47 protons
• 47 electrons
• elemental symbol: Ag
• atomic mass: 107.87
• 61 neutrons

Question 3

mass number

Answer 3

• mass number (a) = number of protons + number of neutrons

- atomic number (z) = number of protons (protons smaller of two numbers)

Question 4

standard format

Answer 4

• mass number
• symbol
• atomic number

Question 5

isotopes

Answer 5

• atoms with the same number of protons but different numbers of neutrons
• carbon-12: 12^C_6 (6 protons, 6 electrons, 6 neutrons)
• carbon-13: 13^C_6 (6 protons, 6 electrons, 7 neutrons)
• carbon-14: 14^C_6 (6 protons, 6 electrons, 8 neutrons)

Question 6

atom notations

Answer 6

• represent the atom with a mass number of 35 and an atomic number of 17
• chlorine-35: 35^C
• Cl-35: 35^Cl_17

Question 7

natural abundance of isotopes

Answer 7

• naturally occurring iron (Fe) consists of four stable isotopes:
• 5.845% of 54^Fe
• 91.754% of 56^Fe
• 2.119% of 57^Fe
• 0.282% of 58^Fe
• naturally occurring bromine (Br) consists of two stable isotopes: 50.69% of 79^Br
• 49.31% of 81^Br