MEDIUM
9th Foundation
IMPORTANT
Earn 100

Read the given statements and mark the correct option.

Statement 1: Solid CO2 changes its state when exposed to air.
Statement 2: CO2 undergoes sublimation.

13.79% studentsanswered this correctly

Important Questions on Matter in Our Surroundings

MEDIUM
9th Foundation
IMPORTANT

Match column I with column II and choose the correct option from the given codes.

Column I Column I
P. Hot tea poured in saucer gets cooled faster. (i) Evaporation increases with increase in temperature.
Q. We feel more cold after a hot water bath than a cold water bath. (ii) Evaporation increases with decrease in humidity.
R. Water is cool in earthen pitcher during dry hot day. (iii) Evaporation increases with increase in wind speed.
S. We feel comfortable under a moving fan in summer. (iv) Evaporation increases with increase in surface area.
MEDIUM
9th Foundation
IMPORTANT

Which of the following curves would be obtained on heating solid naphthalene to a temperature which is above its melting point?

EASY
9th Foundation
IMPORTANT
What is the correct increasing order of molecular motion (kinetic energy) of particles in the following?
EASY
9th Foundation
IMPORTANT
An organic compound X'' has a melting point of -33°C and a boiling point of 66°C . The physical states of substance X'' at temperature -100°C, 0°C and 100°C are respectively
EASY
9th Foundation
IMPORTANT

An experiment is performed as shown in the given figure.

Question Image

The conclusion we can draw from the given experiment is that:

MEDIUM
9th Foundation
IMPORTANT
Fill in the blanks P, Q, R and S left in the table with appropriate words.
Properties Solid Liquid Gas
Inter-particle spaces  Very less Comparatively large P
Intermolecular forces Q Weak Very weak
Compressibility R Very small High
Diffusion Negligible S Very fast

 

  P Q R S
(A) Very large Strong Negligible Slow
(B) Large Weak Small Fastest
(C) Less Strong High Slow
(D) Large Strong Strong Fast

 

MEDIUM
9th Foundation
IMPORTANT

Ritwik was given four inflammable substances P, Q, R and S. He was asked to hand over them to Ramesh who was the resident of a hot area (temperature, 46°C). Ritwik collected the data about the substances as shown in the table. Which substances Ritwik should not carry to the hot area where Ramesh lives?

Substance Ignition Temperature
P 40°C
Q 38°C
R 52°C
S 59°C
EASY
9th Foundation
IMPORTANT
Choose the correct statements about plasma state.
I. The state consists of super energetic and super excited particles.
II. The particles of plasma state are in the form of ionised gases.
III. The plasma is created on stars.
IV. Colour of plasma glow depends on temperature of gas only.