题目

The following questions refer to the Bohr model of the atom.
a>Define an electron shell;
b>Define an electron orbit;
c>In which electron shell are electrons with the lowest possible energy to be found?
d>Electrons travel at high speed.What stops them from flying right away from the nucleus?
e>How big is the nucleus compared with the size of the atom?
f>How heavy is the nucleus compared with the weight of the atom?
g>If we ride a bike quickly around and around a circular track,we use up a lot of energy; we get slower and slower as we run out of energy and eventually stop.Is this what electrons do too?Discuss
(关于化学,全部用英语回答!)

提问时间：2021-04-01

答案

a>
An electron shell,also known as a main energy level,is a group of atomic orbitals with the same value of the principal quantum number n.
b>
An electron orbit is the region in which an electron may be found around a single atom.Specifically,electron orbits are the quantum states of the individual electrons in the electron cloud around a single atom.
c>
shell 1
d>
Because of the electromagnetic attraction between nucleus(protons) and electrons
e>
An atom is about ten thousand times larger than a nucleus in radius.
f>
A nucleus weighs almost equal to the atom it's in.(a nucleus takes more than 99% in weight of a atom)
g>The bike stops because of the resistance comes from ground & air.While in an atom,there's no such kind of resistance.So the electron keeps their circular flying.