Methods Of Separating Mixtures
Handpicking.
Threshing.
Winnowing.
Sieving.
Evaporation.
Distillation.
Filtration or Sedimentation.
Separating Funnel.
Frequency is defined as the number of waves per second. In this machine 25 waves pass in one second.
We need to calculate the number of waves that pass a particular point during one second.
During 2 seconds -25 waves
Therefore in one second - 25/2 = 12.5 waves/s.
1 wave per second has the unit Hertz (Hz)
Therefore answer is 12.5 Hz
Oxidation is a process when an atom, a group of atoms, or an ion loses electrons.
For example,
Cu⁰ -------> Cu⁺² + 2e⁻. This is an oxidation process.
As we can see an oxidation number was 0, and it became +2. The oxidation number is increased. Oxidation number of the atom, when an atom has undergone oxidation, increases.
So, answer is b.False.
A physical change.
Physical change = can be reverted + doesn't change substance
Chemical = changes substance