an atom contains 70 protons, 70 electrons, and 99 neutrons. what is the mass number?\n239\n169\n140\n70\nhypo…

an atom contains 70 protons, 70 electrons, and 99 neutrons. what is the mass number?\n239\n169\n140\n70\nhypothetical element q has 3 isotopes with the relative abundances shown in this table. what is the average atomic mass of element q?\nisotopes of element q\nisotope atomic mass (amu) relative abundance (%)\n1 53 80 %\n2 56 15%\n3 58 5%\na. 55.7\nb. 56.0\nc. 33.3\nd. 53.7

an atom contains 70 protons, 70 electrons, and 99 neutrons. what is the mass number?\n239\n169\n140\n70\nhypothetical element q has 3 isotopes with the relative abundances shown in this table. what is the average atomic mass of element q?\nisotopes of element q\nisotope atomic mass (amu) relative abundance (%)\n1 53 80 %\n2 56 15%\n3 58 5%\na. 55.7\nb. 56.0\nc. 33.3\nd. 53.7

Answer

Explanation:

Step1: Mass number = protons + neutrons

$70 + 99 = 169$

Answer:

169

Explanation:

Step1: Calculate each isotope's contribution

$53 \times 0.8 = 42.4$, $56 \times 0.15 = 8.4$, $58 \times 0.05 = 2.9$

Step2: Sum contributions for average mass

$42.4 + 8.4 + 2.9 = 53.7$

Answer:

d. 53.7