Structure of the Atom — Science STD 9 — Question

When the frequency of the sound is increased, the wavelength __________. (Increases, Decreases, Remains constant)

Evaporation of a liquid at room temperature leads to a ________ effect. (Neutral, Cooling, Heating)

Fill in the blanks with suitable words:
The physical quantity which gives both, the speed and direction of motion of a body is called its __________.

Chemical changes bring a change in the ________ properties of matter. (Chemical, Physical, Structural)

Forces in a Newton’s third law pair have equal Magnitude, but act in opposite __________. (directions, Mass, Velocity)

Isotopes have the same ______ but different Mass number. (Atomic number, Mass number, Valency)

A sulphide ion has a negative charge because it contains fewer Protons than ____________. (Protons, Electrons, Neutrons)