Answer:
Correct answer is A.
Explanation:
Frequency is the number of oscillations that a wave have per unit time. Since time is measured in seconds, the wave with the highest frequency must register the highest number of oscillation per second. Hence, correct answer is A.
Answer:
the chemical change occur in burning paper.
boiling water does not make any chemical change
melting gold "
dissolving sugar in water "
in these examples the reactant remains as the same , even if you melt gold it is gold itself, it only change its state.
The law of conservation of mass states energy can’t be created or destroyed, but can be interconverted. During those processes, you are not creating new molecules, but each molecule undergoes a mechanism to be converted to another.
18.is D
19.is A
hope it's correct
Yes
Methane also is the chief constituent of natural gas, which contains from 50 to 90 percent methane (depending on the source), and occurs as a component of firedamp (flammable gas) along coal seams.
