This thing introduces the fundamental building block of matter and also some the the important group schemes researchers use come communicate around matter. One of the main challenges of this development (and this is true at all levels) is that learners space easily perplexed by the terminology. "Atom" is often perplexed with "molecule" and the distinction between element and also compound is likewise one that learners find daunting to make. For this reason, these concepts and also their explanations space repeated very often transparent the chapter. Us have likewise included plenty of diagrams the what the various classes of issue would look like at the atomic/molecular scale. Since these atoms and molecules are too tiny to see also with a microscope, scientific research educationists use the adjective "sub-microscopic" to refer to diagrams the depict entities on this scale. The capability to imagine chemical occasions as castle would occur on the sub-microscopic range lies in ~ the love of knowledge chemistry and also the importance of arising this ability cannot it is in overstated.

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the is equally vital for learner to have the ability to interpret and draw sub-microscopic diagrams. Us have also built in tasks where learners need to construct molecules making use of plasticine or beat dough, to reinforce the skill. Pat dough is easy and also cheap come make; a cooking recipes follows.

Play dough recipe


2 cup flour 2 cups warmth water 1 cup salt 2 tablespoons vegetables oil 1 tablespoon cream that tartar (optional for enhanced elasticity) food colouring in different colours


Mix all of the ingredient together and also stir over low heat. The dough will start to thicken until it resembles mashed potatoes. As soon as the dough pulls far from the sides and also clumps in the center of the pan, remove the pan native the warm and permit the dough to cool sufficient to handle. Note: If the dough is still sticky, it simply needs to be cooked longer. Turn the dough the end onto a clean surface and also knead vigorously till smooth. Division the dough right into balls because that colouring. Make a tiny depression in the center of the ball, and also pour a little food colouring into it. Work the colour v the dough, adding an ext if you great to rise the strongness of the colour.

1.1 The structure blocks of issue (1 hour)




Activity: A quick revision that the routine Table the Elements

Accessing and recalling information, sorting and also classifying, writing

Suggested (optional revision)

1.2 Sub-atomic particles (1.5 hours)




Activity: Make your own model of an atom

Reading, interpreting, accessing and recalling, making, drawing, labelling, communicating

CAPS suggested

1.3 Pure building materials (3 hours)




Activity: Studying representations of atoms and also elements

Accessing and recalling information, interpreting, reading, writing


Activity: Atoms and also molecules

Accessing and also recalling information, revising


Activity: Writing and understanding basic chemical formulae

Accessing and recalling information, interpreting, sorting and classifying, reading, writing, making, drawing, communicating

CAPS suggested

Activity: Imagining the decomposition of water at the scale of molecules

Accessing and recalling information, interpreting, sorting and also classifying, making, writing,


Investigation: The decomposition that copper chloride

Observing, recording information, interpreting,

CAPS suggested

1.4 mixtures of elements and also compounds (0.5 hours)




Activity: Distinguishing in between elements, compounds and mixtures

Sorting and classifying,


What is matter made up of, at the most straightforward level? What do facets look like at an atomic level? just how are the atom of one aspect different native the atom of one more element? i m sorry table summarises all the aspects known to humanity according to their chemical properties? are atoms the smallest particles making up matter, or space they themselves consisted of of even smaller particles? What do scientists know about the "inside" the the atom? Why execute we to speak atoms are "neutral"? once is a substance "pure"? just how is a compound different from one element? how is a molecule various from one atom? What holds molecules together? What happens to atoms and also molecules throughout a chemistry reaction? how is a mixture of aspects different indigenous a compound?

What is matter? The traditional definition says issue is something that has mass and also occupies volume (takes increase space).

We could say that matter is "stuff", but that would not be really specific. To know matter in a clinical way, we should imagine what the is do of.

all the different varieties of matter that exist on planet are made up of one or more chemical elements. You were introduced to some of the facets in Gr. 7 Matter and Materials. Before reading further, stop and also see just how much you can remember around the elements. Create down what girlfriend remember or speak it out loud.

over there are more than 100 well-known elements and also scientists space still looking for more. We likewise learnt the each element has a distinct name, chemical symbol and atomic number that represents it, in addition to a fixed ar on the routine Table that elements.

The title of this ar is "The building blocks of matter". Because that this reason, we will start our discovery by imagining a wall that has been developed of bricks, favor the one in the complying with picture. Deserve to you see how the wall surface is make of countless identical bricks?

A brick wall.

Similarly, we have the right to think that most develops of issue as being comprised of many, many little particles. These little particles are dubbed atoms.

What are atoms?

The beforehand Greek theorists proposed the all matter is comprised of incredibly little but discrete systems (like the bricks in our wall surface example). Democritus (460 - 370 BC) was the an initial to call these units atomos. From this phrase came the ax atom that we usage today.

Democritus very first used the termatomosmore 보다 2000 years ago to explain the smallest particle that matter is make of. It took a very long time (more than 2000 years!) for the principles of Democritus come be embraced by scientists. Why perform you think it take it so long? talk about this in your class.

Get learner to discuss this in course for a few minutes. You might steer the conversation with the adhering to questions:

execute you believe in vampires? (Fairies, zombies, the Easter Bunny, Thokoloshe, etc.) carry out you think they yes, really exist? once do we know something yes, really exists? (When we have actually hard proof for that existence.) can it be that scientists did not believe in the presence of atoms since they might find no hard evidence for their existence? Why carry out you think scientists might not discover evidence for the presence of atoms? can it be because atoms room so incredibly tiny that they cannot be seen by the naked eye?
Atoms space so tiny that till recently, the was difficult to view them, also using the strongest microscope. Recently there are microscopes connected to sophisticated computer software, which make it possible for researchers to in reality "see" atoms.

deserve to you imagine how an overwhelming it must have actually been to convince those beforehand scientists that matter consists of really, really small particles that no-one has ever before seen?

Atoms room so little that a glass the water contains much more atoms than there are glasses of water in the Atlantic Ocean.

How small are atom really? Well, about 5 000 000 000 000 000 000 the them would fit within the complete stop in ~ the finish of this sentence. Of course different atoms have different sizes, for this reason this is just an almost right number. Wait... Atoms have different sizes? how does that work? In the next section, we will find out.

What room elements?

Democritus" ideas around matter were ignored and also forgotten for more than 2000 years, until an englishman by the surname of man Dalton reintroduced them come the scientific human being in 1803. Dalton made five claims around atoms that are still largely accepted as the truth today. 3 of this claims, or postulates as they are much more commonly called, call us exactly how to recognize elements. Us will obtain to the remaining two postulates later. Here is what Dalton teach us about elements:

Each aspect consists of indivisible, minute particles dubbed atoms.

All atom of a given element are identical.

Atoms that different aspects have different masses.

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This ties in v what us learnt about the elements in Gr. 7 Matter and Materials. Let us revise what we already know:

The routine Table of elements was initially made to stand for the trends observed in the chemical properties that the elements. Each element has a fixed position on the periodic Table. The aspects are arranged in stimulate of boosting atomic number.

The facets are i ordered it in bespeak of increasing atomic number.
friend can find a larger version the the periodic Table on the within cover the your publication for basic reference.