The Particulate Nature of Matter

Question 1

All_____ is made of small particles.

Answer 1

All matter is made of small particles.

Question 2

All matter is made of small_________.

Answer 2

All matter is made of small particles.

Question 3

Particles may be ________.

Answer 3

Particles may be atoms or molecules (group of atoms). There are also substances made up of charged particles called ions.

Question 4

The state of matter: solid, liquid or gas, depends on _____, which is in turn related to the ________ of the particles. Thus the particles are in constant ______.

Answer 4

The state of matter: solid, liquid or gas, depends on temperature, which is in turn related to the average kinetic energy of the particles. Thus the particles are in constant motion.

Question 5

In a solid, the particles are arranged______ in an __________.

Answer 5

In a solid, the particles are arranged close to each other in an orderly arrangement.

Question 6

In a liquid, the particles are held ____________.

Answer 6

In a liquid, the particles are held close together but with no orderly arrangement.

Question 7

In a gas, the particles are__________. The _____ distance between gas particles compared to the size of the _____ means the ____ of gas particles is _______ compared to the volume occupied by the gas.

Answer 7

In a gas, the particles are far apart. The large distance between gas particles compared to the size of the particles means the volume of gas particles is negligible compared to the volume occupied by the gas.

Question 8

The pressure of a gas is due to the _________________.

Answer 8

The pressure of a gas is due to the motion of the particles of gas striking the object bearing that pressure. Pressure is when gas knock against the wall.

Question 9

State the energy content, arrangement, relative movement, forces of attraction between particles, shape and volume, compressibility and a representation model (draw it on a paper) for solids.

Answer 9

The energy content of a solid is lower than liquids or gases. The arrangement of particles in a solid is close together in an orderly arrangement. The relative movement of a solid is that it only vibrates about fixed positions. The forces of attraction between particles of a solid is stronger than in a liquid or gas. The shape and volume of a solid: a solid has a fixed shape and a fixed volume. A solid cannot be compressed. A representation model for a solid are nine circles packed closely, forming a ‘square’.

Question 10

State the energy content, arrangement, relative movement, forces of attraction between particles, shape and volume, compressibility and a representation model (draw it on a paper) for liquids.

Answer 10

The energy content of a liquid is higher. The arrangement of particles in a liquid is held close together in no orderly arrangement. The relative movement of a liquid is that it vibrates, and move randomly, sliding past each other. The forces of attraction between particles of a liquid is weaker than in a solid. The shape and volume of a liquid: a liquid has no fixed shape but a fixed volume. (Takes the shape of the container). A liquid cannot be compressed. A representation model for a liquid can be found in your notes—> the particulate nature of matter.

Question 11

State the energy content, arrangement, relative movement, forces of attraction between particles, shape and volume, compressibility and a representation model (draw it on a paper) for gases.

Answer 11

The energy content of a gas is much higher. The arrangement of particles in a gas is widely spaced apart with no orderly arrangement. The relative movement of a gas is that it vibrates, and move randomly and freely. The forces of attraction between particles of a gas is very much weaker than in solids and liquids (negligible). The shape and volume of a gas: a gas has no fixed shape and no fixed volume. (Fills the container). A gas can be compressed. A representation model for gases can be found in your notes—> the particulate nature of matter.

Question 12

What are the changes in state (process) from liquid to solid and from solid to liquid?

Answer 12

liquid to solid: freezing
solid to liquid: melting

Question 13

What are the changes in state (process) from liquid to gas and from gas to liquid?

Answer 13

liquid to gas: boiling
gas to liquid: condensation

Question 14

What are the changes in state (process) from solid to gas and from gas to solid?

Answer 14

solid to gas: sublimation
gas to solid: vapour deposition

Question 15

What are some examples of sublimation?

Answer 15

Iodine (can melt depending on the temperature) /mothballs, CO2 (small 2), dry ice

Question 16

What is the forth state of matter?

Answer 16

Plasma

Question 17

What is the fifth state of matter?

Answer 17

Bose-Einstein Condensate (BEC).

Question 18

What is the sixth state of matter?

Answer 18

Fermionic Condensate

Question 19

A graph shows the variation in temperature with time as a sample of ice is heated from -10 degrees celcius to -110 degrees celcius. Visualise and explain how the graph will look like and why is that so.

Answer 19

only ice (solid water) is present from ta to tb

both ice and water are present from tb to tc

only gaseous water is present from te to tf

Question 20

Explain why temperature does not decrease when a liquid freezes to solid.

Answer 20

When liquid water is cooled, e.g. from 10 degrees celcius to 0 degree celcius, the water particles decrease in avergae kinetic energy and so decrease in motion.

At 0 degree celcius, the particles cease to slide over each other and become held in fixed positions and in an orderly arrangement. The particles only vibrate about their fixed positions. The substance is now a solid.

Heat energy is released as the particles attract each other to take on the arrangement as a solid. This is the opposite of melting, where heat energy is absorbed to overcome the forces of attraction between solid particles.

The heat energy released compensates the heat energy lost due to the continued cooling. This explains why the temerature remains at 0 degrees celcius until all the liquid particles stop moving past each other and become fixed in position. After freezing is complete, further cooling (removal of heat) results in the decrease in temperature of the ice.

Question 21

What happens during melting?

Answer 21

The solid particles absorb heat energy, thereby overcoming the attractive forces holding them together.

Question 22

What happens during freezing?

Answer 22

• liquid particles lose kinetic energy as cooling takes place
• the particles do not have sufficient lower energy to overcome the attractive forces i.e. the attractive forces can now hold the particles close together.

Question 23

What are the similarities of elements and compounds?

Answer 23

Both are made up of particles (atoms) which are the building blocks.
Both are pure substances.
Both have fixed melting and boiling points.

Question 24

What are the differences between elements and compounds?

Answer 24

An element is made up of only one type of atom.
An element can be metallic or non-metallic. A compound can be formed by combining a metallic element with a non-metallic element, or combining 2 or more non-metallic elements.

An element cannot be chemically split into simpler substances. A compound can be decomposed into its elements or simpler compounds.

Question 25

What are the similarities between compounds and mixtures?

Answer 25

Both are made up of more than one type of atom.

Question 26

What are the differences between compounds and mixtures?

Answer 26

A mixture can be separated into its components by physical methods. A compound can only be separated into its elements by chemical methods. A mixture does not have a fixed melting or boiling point. A compound has a fixed melting and boiling point. No chemical changes take place when a mixture is formed. A chemical changes takes place when a compound is formed. The proportion of the constituents in a mixture can vary. The elements are always combined in a fixed proportion by mass in a compound. The properties of a mixture are the same as those of its constituents. The properties of a compound differ from those of its constituent elements.

Question 27

What is the definition of a mixture?

Answer 27

- contains two or more substances physically together but not reacted with one another chemically.

Question 28

What is the definition of a compound?

Answer 28

- contains two or more elements chemically combined together.

Question 29

The phenomenon of _________ is cited as an evidence that matter is made of particles.

Answer 29

The phenomenon of diffusion is cited as an evidence that matter is made of particles.

Question 30

Define diffusion.

Answer 30

Diffusion is the movement of particles from an area of high concentration an area of low concentration

Question 31

Molecules can only be elements. True or false?

Answer 31

False. Molecules can be elements or compounds. For example oxygen (02 small 2) is a molecule, and compounds like water (H20 small 2) has a molecule H2 (small 2) —> hydrogen. Thus, molecules can be elements or compounds.

Question 32

If a substance is pure, there is no ______ just one ______ when it boils or melts.

Answer 32

If a substance is pure, there is no range, just one temperature when it boils or melts.

Question 33

When 50cm cube of water is mixed with 50 cm cube of ethanol, the total volume of the resultant solution was lower than 100 cm cube. Explain this observation in terms of the distribution of particles.

Answer 33

The water molecules fit into the spaces between the ethanol molecules. Thus the total volume of the mixture is smaller than expected.

Question 34

Which of the following substances has the lowest amount of kinetic energy? Ice at negative 10 degrees celcius Ice at 0 degrees celcius Water at 0 degree celcius Dry ice (solid carbon dioxide) at 0 degrees celcius

Answer 34

Answer: ice at negative 10 degrees celcius In general, solids have the lowest amount of kinetic energy and gases have the highest amount of kinetic energy. For substances in the same state, the substance at the lower temperature will have a lower amount of kinetic energy.

Question 35

A gas is held in a closed container and the container is heated gradually. Which statement(s) is/are true? Kinetic energy of the particles in the gas will decrease. The particles in the gas will still move in a continuous and random motion. There will be more collisions between the particles in the gas.

Answer 35

Feedback The second option is correct. The particles that made up matter are in continuous and random motion. This is true at any temperature. Feedback The third option is correct. The particles in the gas will collide with each other more often as they have more kinetic energy and move faster.

Question 36

Which statement(s) regarding diffusion is/are correct? The rate of diffusion of particles depends on the temperature of a substance. Diffusion can explain the spread of perfumes and cooking aromas. Ink is able to spread out when it is dropped into a beaker of water because the water and ink particles move randomly in the beaker of water. Diffusion from a region of higher concentration to a region of lower concentration will not occur when the temperature reaches 0 °C for a substance with a freezing point of -20 °C.

Answer 36

Feedback The first option is correct. The rate of diffusion of particles depends on the temperature of the liquid or gas. The higher the temperature of the liquid or gas, the higher the rate of diffusion of the particles in the liquid or gas. Feedback The second option is correct. The particles from the perfumes and cooking aromas are able to diffuse from a region of higher concentration to a region of lower concentration. Feedback The third option is correct. Diffusion occurs when the water and ink particles move randomly and collide with one another in the beaker of water.

Question 37

A sample of salt solution was subject to temperature changes. Which of the following is most likely to be observed? A It starts freezing at 1 degrees celcius and boiling at 98 degrees celcius. B It starts freezing at 1 degree celcius and boiling at 102 degree celcius. C It starts freezing at -2 degrees celcius and boiling at 98 degrees celcius. D It starts freezing at -2 degrees celcius and boiling at 102 degree celcius.

Question 38

Which of the following substances would boil at a fixed temperature? A concentrated hydrochloric acid B liquefied air C molten copper (II) chloride D molten steel

Answer 38

C