Answer:
Photon of light
Explanation:
According to Bohr's model of the atom, electrons in atoms are found in specific energy levels. These energy levels are called stationary states, an electrons does not radiate energy when it occupies any of these stationary states.
However, an electron may absorb energy and move from one energy level or stationary state to another. The energy difference between the two energy levels must correspond to the energy of the photon of light absorbed in order to make the transition possible.
Since electrons are generally unstable in excited states, the electron quickly jumps back to ground states and emits the excess energy absorbed. The frequency or wavelength of the emitted photon can now be measured and used to characterize the transition. This is the principle behind many spectrometric and spectrophotometric methods.
The answer is True . The precision of a measuring is based on the fitness of its scale subdivisions
The answer to this question would be: BaCl 2
Barium is an alkali metal with 56 atomic number. Barium located in the group 2 of the periodic table because it has 2 valence electrons. Chlorine is a nonmetal that has 1 valence electron. When react, it would need 2 chlorine for each barium as the valence electron of barium is twice the chlorine.
Answer:
112 mL
Explanation:
The formula for percent by volume is
If you have 250 mL of a solution that is 44.8 % v/v,
Answer:
Explanation:
The work function of the sodium= 495.0 kJ/mol
It means that
1 mole of electrons can be removed by applying of 495.0 kJ of energy.
Also,
1 mole = 
So,
electrons can be removed by applying of 495.0 kJ of energy.
1 electron can be removed by applying of 
of energy.
Energy required = 
Also,
1 kJ = 1000 J
So,
Energy required = 
Also, 
Where,
h is Plank's constant having value 
c is the speed of light having value 
So,
Also,
1 m = 10⁻⁹ nm
So,
