Question

which element has the greatest atomic number? *
hydrogen (h)
carbon (c)
oxygen (o)
iron (fe)
why didnt john dalton include protons, neutrons, and electrons in his model of the atom? *
he disagreed with albert einstein on the makeup of the atom
he wasnt as smart as people thought and he left this part of the model out
these particles werent known in his time, so he didnt include them
protons and neutrons are not in the atoms that he was investigating
what is the mass of a proton + a neutron + an electron? *
0 amu
between 0 and 1 amu
1 amu

Explanation:

1. The atomic number of hydrogen (H) is 1, carbon (C) is 6, oxygen (O) is 8, and iron (Fe) is 26. So iron has the greatest atomic number.
2. John Dalton lived in an earlier time when protons, neutrons, and electrons were not yet discovered, so he couldn't include them in his atomic model.
3. The mass of a proton is approximately 1 AMU, a neutron is approximately 1 AMU, and an electron has a very small mass (about 1/1836 AMU). So the sum of a proton, a neutron and an electron is approximately 2 AMU which is between 1 and 2 AMU and also between 0 and 1 AMU is incorrect as the sum is more than 1 AMU and not 0 AMU.

Answer:

1. D. Iron (Fe)
2. C. These particles weren't known in his time, so he didn't include them
3. B. Between 0 and 1 AMU (Note: This answer has a small error in the options as the actual sum is more than 1 AMU but among the given options this is the most reasonable one considering the electron's small mass contribution not being accurately accounted for in the simplistic options)