which of the following ideas is not retained in the current theory of atomic structure?

Question

a. Most of the volume of an atom is empty space
b. Electrons move around the nucleus as planets orbit the sun
c. Electrons can absorb or emit energy only in whole numbers of photons

d. Atoms have a central positively-charged nucleus

Answer 1

b.
Current theory holds that unlike a planetary body orbiting the sun, with known momentum and position, the position of an electron at any given moment can only be described as a probability. Electrons seem to pop in and out of existence, with 10% of their time unaccounted for. This would be akin to the moon being where we would expect to see it 90% of the time, but the remaining 10% would be unpredictable. Of course this analogy only applies to subatomic particles. The uncertainty of where that electron is, is described by the Heisenberg Uncertainty Principle.

Answer 2

The atom contains a nucleus which consists of protons, neutrons and electrons which orbit the nucleus. Protons have a +1 charge, neutrons have no charge and electrons have a -1 charge therefore the overall atom is neutral as the + and - charges cancel each other out. Electrons orbit the nucleus in different energy levels/shells. The further away the electron is from the nuleus, the more energy it has. Electrons are arranged using the S,P,D,F notation. The S sub-level can hold 2 electrons. The P sub-level can hold 6 electrons. The D sub-level can hold 10 electrons The F sub-level can hold 14 electrons. If two electrons occupy an orbital, one must be spin up and the other a spin down Hope I helped :)

Answer 3

That's got to be option b.

b. Electrons move around the nucleus as planets orbit the sun

One cannot predict the position and momentum simultaneously due to Hiesenberg uncertainity principle. Instead they are represented in terms of probability i.e. as electron clouds. Thus this statement is incorrect!

Answer 4

b. We've moved on from the planetary model. Electrons are now seen as occupying cloudlike shells of space in which they have a certain probability of being found, instead of objects on fixed paths.

Answer 5

d. atoms have a central positivley-charged nucleus
the nucleus has both positive and neutral charge

Answer 6

The universe is held together by Silly String! That's "Dikkus' silly string theory."

Answer 7

b. Electron orbitals are now known to be clouds, rather than discrete circles/ellipses.

Answer 8

b. We know that electrons move as a cloud.

Answer 9

b

Answer 10

B