helium group no val elect
mg is reactive when activated. when burned, very intense
pot\asssium 1 valence elect ... KCl eg
theone with H and sodium in it
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A. Through the direct contact of particles
Answer:
True
Explanation:
The atomic mass of oxygen is 16amu, which means the <em>molar mass</em>, the mass of one mole of oxygen atoms (1 mole = 6.02x10²³), is 16g.
Answer: The frequency heard will be f = 275.675Hz
Explanation: When an object emitting sound is moving, it occurs a phenomenon called Doppler shift or Doppler effect. What happens is that the sound gets higher when the moving object comes closer the observer and becomes lower after it passes, This change is due to the quantity of waves that passes through an area in an unit of time.
The formula to calculate the Doppler effect is as follows
f = (
) · f₀
f is the observed frequency;
c is the speed of sound;
Vs is velocity of the source;
f₀ is the emitted frequency of source;
Substituting and calculating,
f =
· 300
f = 275.675 Hz
Thus, the frequency heard by the police officer is 275.675Hz.