lesson 2 - 2sec

Electron transfer from E4 to E1 what do you expect the colour released ?

• Red

• Violet

The reason that we can't say 2Q or 3Q

• The distance between the energy levels are not equal

• The energy between the energy levels are not equal

• The energy between the energy levels are equal

• The distance between the energy levels are equal

Different colours in the spectral line because of ?

• Different energy released from the transfer the electron back to it's original level

• Different energy released from the transfer the electron back to higher energy level

• same energy released from the transfer the electron back to higher energy level

Bohr postulates include :

• electron transfer in a rapid movement without or absorption of any amount of energy and it is called excited atom

• electron orbit the nucleus in a definite allowed energy levels , they can be found at intermediate distances .

• each electron has a definite amount of energy depending on the distance between the nucleus and energy level

• when an electron acquire a quantity of energy it jumps to a higher energy level forever

atomic spectra was the key which solved the puzzle of the atomic structure

• True

• False

The light emitted from a fireworks display is produced when electrons in an excited state

• Absorb energy as they move to lower energy states

• Release energy as they move to higher energy states

• Release energy as they move to lower energy states

• Absorb energy as they move to higher energy states

Which statement describes how an atom in the ground state becomes excited?

• The atom releases energy, and one or more electrons move to a higher electron shell.

• The atom releases energy, and one or more electrons move to a lower electron shell.

• The atom absorbs energy, and one or more electrons move to a lower electron shell.

• The atom absorbs energy, and one or more electrons move to a higher electron shell.

Based on the line spectra above, identify the two gases present in the mixture.

• Gas A + Gas D

• Gas A + Gas C

• Gas C + Gas D

• Gas A + Gas B

An electron in a calcium atom gains enough energy to move from the first shell to the second shell. The calcium atom becomes

• A positive ion

• An atom in the ground state

• An atom in an excited state

• A negative ion

Which of the following describes how colors in a line spectrum or in a fireworks display are produced?

• Ions in salts release a specific amount of energy as the electrons move from a lower energy state to a higher energy state (excited state)

• Ions in salts release a specific amount of energy as the electrons move from a higher energy state (excited state) to a lower energy state

• Ions in salts absorb a specific amount of energy, moving to a lower energy state as a result

• Ions in salts absorb a specific amount of energy and become excited