Neils bohr measured the eneray required to move the electron
hydrogen atom out of its ground state and the energy emitted when the
electron returned to its ground state. what did he learn about the structure of
the atom from this information?
a. the existence of the electron.
the law of multiple proportions.
c. the existance of the nucleus
d. that the electrons reside in the electron cloud in shells (or energy
levels) with fixed amounts of energy.

1 a

2 d

3 a

4 c

explanation:

there is none because earth is stationary and flat.

the answer is option a.

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally