Answer:
A star is made up of burning gases, while a comet is made up of ice, gases, rocks, and dust.
Explanation:
Answer:
He developed the concept of concentric electron energy levels
Explanation:
Before Bohr's model, Rutherford's model was proposed. This model explains most of the properties of the atom but failed to explain the stability of the atom.
As per Rutherford's model, electrons revolve around the nucleus in the orbit.
But revolving electron in their orbit around nucleus would give up energy and so gradually move towards the nucleus and therefore, eventually collapse.
Bohr's proposed that the electrons around the nucleus move orbit of fixed energy called "stationary states". Electrons in these stationary states do not radiate energy.
Therefore, proposal of concentric electron energy levels refine the atomic models.
There is 6.02*10^23 molecule per mole. And there is 2 atoms per oxygen molecule. So the answer is 1.204*10^24 atoms in 1.0 mole of O2.
False, kinetic energy depends on an objects mass and speed
