TERM 3 - Solids, Liquids and Gases

Question 1

What is matter?

Answer 1

A substance which has mass and takes up space.

Question 2

What is a fluid?

Answer 2

A fluid is a substance that is a liquid or gas and has the property of being able to flow.

Question 3

What is diffusion?

Answer 3

Diffusion is the act of a gas dispersing inside a container to take up all available space. A liquid diffuses in another liquid, but not in a solid or gas.

Question 4

What is the meniscus and what is a parallax error?

Answer 4

The meniscus is the dip in the water as the water curves up onto the sides of its container. A parallax error is a sight error due to seeing an object at different lines of sight and thinking that object is therefore positioned at a different place to what the other line of sight looked like.

Question 5

What are the changes of states called? (e.g. gas to liquid, liquid to solid, solid to gas ect.)

Answer 5

When matter is cooled the process is called condensation for a gas to liquid, solidification for a liquid to solid, and deposition going from a gas to a solid.

When matter is heated the process is called melting for a solid to a liquid, evaporation for a liquid to a gas, and sublimation for a solid to a gas.

Question 6

What are the four major assumptions of the particle model of matter?

Answer 6

1. All matter is made up of tiny particles.
2. The particles of matter are always moving.
3. The particles have spaces between them.
4. Adding heat to matter makes the particles move faster.

Question 7

Why do substances expand as they’re heated, according to the particle model?

Answer 7

The particle model states that adding heat makes the particles move faster, and so the spaces will likely get larger based on the particle model.

Question 8

Why are gases easily compressible under the particle model?

Answer 8

Gases are easily compressed as their particles are spread out, leaving plenty of room for the substance to be compressed into a smaller area. Matter can expand or contract like this due to energy creating a presence or a lack of gaps space in between particles in the substance.

Question 9

Why do changes of state happen? What changes in the behavior of the particles as substances are heated and cooled?

Answer 9

Changes in state happen due to the increase or decrease of energy, and so energy flows out when a substance change from a gas or liquid to a liquid or gas. When the temperature cools and energy flows out the particles slow down, while when the temperature increases the particles speed up as they have more energy.

Question 10

What is data accuracy, precision and uncertainty?

Answer 10

Data is accurate if it gets one near spot-on answer. Data is precise if you consistently get the same result, and the uncertainty of data is a measurement of how precise the data was as a percentage by comparing the results and how much they differed.

Question 11

What are elements, molecules, compounds and mixtures?

Answer 11

Elements are substances that are made up of only one atom, while molecules are still small like atoms but may be made up of two or more atoms. Compounds are elements which are chemically bonded and cannot be removed by processes such as filtration. Mixtures are substances with atoms not completely chemically bonded and so they can be separated by physical processes.

Question 12

What is an atom made of? Where are these particles located within the atom?

Answer 12

An atom is made up of a nucleus and electron shells. The nucleus harbors the protons and neutrons, all in one clump, while the electron shells house the electrons. The nucleus is just a ball of protons and neutrons, while the electron shells are rings which rotate around the nucleus.

Question 13

What is the atomic number, chemical symbol and atomic mass of an element?

Answer 13

Each element has an atomic number, which is the number of protons within it, a chemical symbol, which stands for the element in chemical equations and similar things and is derived from the element’s Latin root, and an atomic mass which is the combined value of the protons (1), neutrons (1), and electrons (0.008).

Question 14

Are the physical properties of compounds dependent on the physical properties of the elements which make them up?

Answer 14

The physical properties of compounds are not dependent on the elements they’re made up of as the elements react differently when put together.

Question 15

Can compounds be separated by physical processes?

Answer 15

Compounds, due to them being chemically bonded, can only be separated from compounds by a chemical reaction and not by a physical change.

Question 16

Can a mixture be separated by physical processes? If so, why?

Answer 16

A mixture is not chemically bonded like a compound is, and so physical processes such as filtration can separate the elements within a substance. A good example of this would be desalination, which is a process that can remove salt from salt water because the salt particles are not chemically bonded to the water particles.

Question 17

What are the properties of metals?

Answer 17

Metals have high melting points, are good conductors of heat and electricity, are dense and are malleable.

Question 18

What are some of the special groupings on the periodic table?

Answer 18

Alkali Metals, Alkali Earth Metals, Transition Metals, Halogens, Noble Gases

Question 19

What are some properties of substances?

Answer 19

All substances which don’t have the same composition have different ways of reacting to different things. Some substance properties are weight, more flammability, can absorb more heat without changing state, are toxic and more.

Question 20

What are some chemical properties of a substance?

Answer 20

Chemical properties includes toxicity, flammability and some others.

Question 21

What’s a physical change? What’s a chemical change?

Answer 21

A physical change isn’t changing the bonds in a substance; it’s simply changing what’s in the substance. A chemical change changes not only what’s in the substance but also the chemical bonds as well.

Question 22

What is a chemical reaction?

Answer 22

A chemical reaction is a chemical change in which a whole new substance is produced.

Question 23

What are the reactants and products of a chemical reaction?

Answer 23

The reactants of a chemical reaction are the initial substances used to cause the reaction. The products are the substance(s) which are there as a result of this chemical reaction.

Question 24

What is some evidence a chemical reaction has occurred?

Answer 24

Evidence that a chemical reaction’s occurred includes things such as a difference in physical properties, a new substance being formed, and some others.

Question 25

What happens to the particles as a substance is heated or cooled?

Answer 25

When the temperature cools, there becomes less energy in the particles and so they slow down. When the temperature heats, there becomes more energy in the particles and so they speed up. That’s why gases, then liquids, and then solids respectively decrease in their ability to flow and have less energy. That’s also why melting point is below boiling point.

Question 26

What are the properties of metalloids?

Answer 26

Metalloids are good semiconductors, are normally solids, are usually brittle, and typically behave as non-metals in a chemical reaction.

Question 27

What are the properties of non-metals?

Answer 27

Non-metals have lower melting points, are brittle, are poor conductors of electricity or heat, and gain electrons easily.

Question 28

What are properties of Alkali metals?

Answer 28

Alkali Metals – Have high thermal and electrical conductivity, are ductile and malleable, all have a single valence electron, and are all highly reactive.

Question 29

What are the properties of Alkali Earth metals?

Answer 29

Alkali Earth Metals – Have two valence electrons, but they share their other properties with alkali metals.

Question 30

What are the properties of Transition metals?

Answer 30

Transition Metals – Are very hard, form coloured compounds, but shares the rest of its properties with alkali and alkali earth metals.

Question 31

What are the properties of Halogens?

Answer 31

Halogens – Have seven valence electrons, are toxic and produce sodium salt with similar properties, but apart from that they aren’t too similar.

Question 32

What are the properties of Nobel Gases?

Answer 32

Noble Gases – Are odorless, colourless, non-flammable gases which aren’t very reactive and possess 8 valence electrons.