Age 8

Rachitha (8) asked “Which of the following is not a pure substance A.common salt B.sugar C.rain water D.iron

sciencemaster Age 8

Rachitha, below is a small animation about some pure substances and impure substances.

This animation initially suggests that Sugar, Water and Lemon Juice are pure substances.

The word Pure in science has a special meaning. Something is pure if it is only one substance, not a mixture of different substances …….so the sugar, water and lemon juice are considered pure. Lemonade is a mixture of these pure substances so it cannot be considered as pure.

However, it could be argued that the juice of a Lemon is not pure. It has a sharp taste which suggests that it is an acid. It does in fact consist of a MIXTURE of three acids so it is not pure.

A.  SALT is however pure it only contains a substance called Sodium Chloride.

B. SUGAR is pure if in only contains a substance called Sucrose

C. RAIN WATER is pure if it only contains a substance called H2O.

D. IRON is pure if it only contains Iron atoms. (if you add Carbon to the iron you get a mixture called Steel)

Like the juice of Lemons .. if any of the above (A,B,C or D) contain anything else they will not be pure.

“What does “eco” in ecosystem mean?” asks Austin (8)

sciencemaster Age, Age 8, All Answers, animals, Environment, life cycle, plants, science

I will just add a few words myself. Thanks for your input.

I like the idea of an ant’s nest being an example of an ecosystem. The nest is ‘everything’ it’s a home, a place to live and to work from, a creche for baby ants, a food store, a food production place, a protective environment, maybe an ant hospital, and lot’s more. It is an ecosystem.

The word ‘eco’ also combines with ‘logy to form ‘ecology’. This is like the word ‘bio’ combining with ‘logy’ to form ‘biology’.  The word ‘logy’ is a word which originally described lots of learning.

I will stop now. For an eight year old I think everything gets very complicated. I very much like the ant’s nest described as an ecosystem.Maybe you could let me know of other ecosystems?

STOP

Will (8) asks “What makes seeds grow?”

sciencemaster Age, Age 8, All Answers, Environment, fair testing, measurement, Nature, plants

 

Will, thank you for your question. Let’s start with some interesting questions. Answers to these might help in answering your question. Firstly is a fruit a seed?  If it is not a seed then what is it for? Does it help the seed grow? How will we know if the seed is growing? What does a seed need to grow? Does it need soil? Do seeds grow when it is cold? Do different seeds grow at different speeds? What do you think? Are there any more questions? Remember questions are what science is all about. By investigating questions you are building knowledge of the world around you.

So, let’s think about how we could investigate some of these questions. Shall we look at just one type of seed, or choose a variety of different seeds to investigate? Maybe looking at one type of seed would help us begin to answer some of the questions. We could then look at another type of seed and compare the results. Maybe one seed would grow faster than the other?

Now we have to think about the conditions for our growing experiment ….. soil/no soil, wet/dry, light/no light, hot/cold. Even for our selected seed this can be very complicated. Can you see why?

The investigation equipment could probably be obtained at home. A empty plastic bottle, with the top cut off, would be a good holder for the seed. Some cotton wool could act as soil. A cupboard and a refrigerator could also help you create the right environment.

Let me know how it went?

“How do people survive in the jungle?” asks Lachlan (8)

sciencemaster Age 8, All Answers, Investigations, Nature, Ourselves, science

Thank you team, for your comments.

You are right Homo Sapiens survived because of their hunting and gathering skills.They were better at it than their fellow humans  Homo Neanderthal and the other human groups (Homo erectus, Homo ergaster, Homo rudolfensis …..)

Some clever people have found, that we still have hunting and gathering skills in our blood. So there you are, we will/might be able to cope in a jungle environment.

Revised 11/11/17 – added other homo species.

“How is porcelain made?” asks Kaia (8)

sciencemaster Age 8, All Answers, Materials, rocks, the 'earth'

Thanks team.There has already been a mention of kaolinite in a question on minerals, see this site.  My team are correct, the difference between ordinary clay pots and porcelain pots is the temperature at which the clay is ‘fired’.

The ‘firing’ process  is linked to the temperature of the kiln.

So a porcelain pot is a pot heated up to much higher temperature than that of other pots. This causes the clay to form a new mineral called Mullite.

For more ‘hardness’ information you can go to this Science Master Special.

Updated 15/01/18 Experiment added.

“How many living things are on Earth?” asks Kaia (8)

sciencemaster Age 8, All Answers, animals, Nature, plants

Thanks team.

If you want a definition of ‘living’please click on the link.

The species  butterfly has  20,000 of the 1 million species in the insect group. At any one time there must be thousands of living Cabbage White butterflies flying around so you have 20,000 different types of butterfly flying around and maybe there are 50,000 of each type living at any one time.  Help. I must admit the calculations are frightening so i cheated and looked at the work of other scientists who say that there are  8 million species and each species has millions of living specimens. 

The homo species (us) has 9 billion living specimens, I suspect the ant population is considerably bigger than that so in answer to your question …. and then think of the number of plants  ….and then the number of bacteria …..there is no believable answer. However somebody has tried and they had difficulty putting all the numbers on their sheet of paper. Sorry Kaia.

If there are other questions which you may have thought of then please fill in the Reply box below or ask another question.  

Revised 17/102017  Numbers on image changed and text rewritten.

Lexi (9) and Jaeda (9) and Cadence(8) asked a question on “Minerals”

sciencemaster Age 8, Age 9, All Answers, Chemical, element, Energy, Materials, rocks, the 'earth'

Lexi, a nice question, a lot of elements are found within the form of a mineral. I shall let my team introduce the answer to this question.

Jaeda. You asked a question on crystals and why are they so expensive. This is not  a science question however most crystals are minerals so this question is also addressed to you.

Cadence . You asked about talc, which is a mineral.

All minerals are found in rocks. It is thought that some are created by the magma (lava) from volcanoes while other were formed in the Earth’s mantle and have reached the surface through earthquake activity. The minerals created from volcanoes have smaller crystals (probably cooled faster), minerals created more slowly in the mantle consist of bigger crystals. All of the minerals are created by a chemical reaction.

A lot of minerals are mined, dug from underground shafts. A lot of minerals have the elements Silicon and  Oxygen in them.Talc is a mineral of the elements Magnesium, Silicon and Oxygen and is mainly found in Japan and the United States.

Have fun and watch this video on minerals.

Thank you Lexi, Jaeda and Cadence. If you want to comment on this post please feel free to do so in the Reply box below. Or why not ask another question.

“Why do stars twinkle” asked Mia (8)

sciencemaster Age 8, All Answers, gases, Investigations, Universe, water

Many thank team. I think Mia has all she needs for a little bit of experimentation.

Mia, in a darkened room , put the aluminum foil on the floor, place the bowl over it and shine the torch onto the bottom of the bowl.

What do you see?

Now add some water to the bowl(about half full). Let the water settle and then shine the torch onto the bottom of the bowl.

What do you see?

Finally, still shining the torch onto the bottom of the bowl give the water a bit of a vigorous stir with a spoon or even the end of a pencil.

What do you see?

Is what you see when the water is moving different from when it is not moving? Maybe the moving water is a bit like the moving air through which you are seeing the stars.

Tell us what you see. you can do this in the Reply box below.
(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

“What was the first plant that ever grew on Earth?” asks Mahdiyat (8)

sciencemaster Age 8, All Answers, fair testing, Investigations, plants, Universe

So what now? Thanks team, some good answers.

It would be great if we could do some small investigations using Moss.

1.Firstly let us confirm that the moss has no stems or flowers.

2. Secondly a more long term experiment. Try ‘planting’ your moss on a rock. Before planting look closely at the surface of the rock. compare the surface 6 months after planting (and not disturbing the Moss).

Now a story ……..

The moss was the Earth’s first plant and it took over the world. It damaged the rocks it settled on and it took all of the Carbon Dioxide out of the atmosphere. This made the Earth very very cold (the first ice age). The coldness killed most of the moss and as the Carbon Dioxide built up again it allowed other plants to share the Earth with it.

(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

“I know I can see myself in a mirror but why cannot I see myself in other things?” asks Isabella (8)

sciencemaster Age 8, All Answers, fair testing, Light, reflection

Many thanks team. I have some ideas about investigations that you could do at home. People say that light travels in straight lines. How can we test this idea. Firstly we need a source of light. How about a torch. 

Now we know that a torch sends out light in all directions but how do we know if it is travelling in a straight line? Think……..

Now lets ‘capture a little bit of the light from the torch. Let’s use a piece of card with a hole in it and see if we can make the light from the torch go through the hole.

Now what do we have to do to show that, the little beam of light coming through the hole is travelling in a straight line?
Supposing we had another piece of card with a hole in it in exactly the same spot do you think you could arrange it so that the little beam of light goes through the hole in the new piece of card?

Do the same for a third piece of card arranging it so the little beam goes through it’s hole. Now draw a line between the torch and the third hole. What do you notice?

Now lets quickly look at your question about not seeing reflections in materials that are not mirrors.

Reflections are wonderful things and they happen, or do not happen because light travels in straight lines. A reflection occurs when a beam of light bounces off a surface. You could set up your torch and card above to make a reflection, using a mirror or something flat and shiny.

Now do the same for a different type of surface.try it with a piece of material. What happens? Try with all sorts of flat surfaces – shiny metal (use flat aluminum foil and then crinkle it), cardboard, paper, plastic, water, leather……..
What do you notice? Maybe reflection requires a flat shiny surface? Think about the results.