<h3><u>Answer;</u></h3>
The period of the wave is <u><em>4 seconds</em></u>
<h3>
<em><u>Explanation;</u></em></h3>
- <em><u>The period of a wave or periodic time is the time taken for one complete oscillation to occur.</u></em> In this case, one complete oscillation occurs when the wave moves from one crest to the next or a trough to the next. <em><u>This takes 4 seconds. Therefore the period is 4 seconds.</u></em>
- <em><u>Frequency on the other hand is the number of oscillations by a wave in one second. Thus, f = 1/T, that is frequency is the reciprocal of periodic time.</u></em>
Answer:
gases Z and Y.
Explanation:
Photons are emitted when electrons jump from a higher energy level to lower energy level and these photons carry light energy.
The light emitted at various wavelengths produce emission spectrum, when viewed via a spectroscope.
While analyzing the image, we could see that the spectrum of unknown sample contains the gases Z and Y.
Answer: metals, non metals and semi metals
Explanation: