Hi all :)

I’ve got my 5yo boy sleeping over every weekend now, and I’d like to do some more science experiments with him. We currently have a jar in the backyard that is growing blue sugar crystals that we made last week.

I’ve been watching some videos and getting ideas, but I’ve come across one that I’m unsure about. This one I won’t be doing with him, but I’m curious to know about it.

This video here shows hand sanitiser being put on a plank of wood, then set alight. It creates a blue flame. That’s fair enough, but then they put their hand into it and pick it up and squish it between their fingers. I’m wondering why the person’s fingers don’t end up getting burnt?

And also the same video but earlier on (link direct to time here), shows dishwashing liquid, butane gas and a bowl of water. Put them together to create a plate full of bubbles, set alight, and then picked up by hand. Their whole hand is engulfed in yellow/orange flame, but again why is their hand not burnt?

JTQ said:

Hi all :)

I’ve got my 5yo boy sleeping over every weekend now, and I’d like to do some more science experiments with him. We currently have a jar in the backyard that is growing blue sugar crystals that we made last week.

I’ve been watching some videos and getting ideas, but I’ve come across one that I’m unsure about. This one I won’t be doing with him, but I’m curious to know about it.

This video here shows hand sanitiser being put on a plank of wood, then set alight. It creates a blue flame. That’s fair enough, but then they put their hand into it and pick it up and squish it between their fingers. I’m wondering why the person’s fingers don’t end up getting burnt?

And also the same video but earlier on (link direct to time here), shows dishwashing liquid, butane gas and a bowl of water. Put them together to create a plate full of bubbles, set alight, and then picked up by hand. Their whole hand is engulfed in yellow/orange flame, but again why is their hand not burnt?

You know it’s time, get him something he can use.

PermeateFree said:

You know it’s time, get him something he can use.

http://forums.pelicanparts.com/uploads22/k+bigpic1367511546.jpg

If we were in america, i’d expect his mother would have already gotten him one.

I’m 36 and never even held a real gun.

In both cases, the liquid is evaporating from the skin; the latent heat (due to the change of state) absorbed from the hand stop the hand from burning. The blue flame in the hand sanitiser is characteristic of alcohol flames, and you can see it if you set fire to a small amount of metho. If you remove any hairs from the back of your hands (and assuming you have no hair on your palms) you can put some metho on your hands and set fire to it. It also burns with a blue flame, and doesn’t burn you because the alcohol is evaporating.

Arts is your person for children’s science experiments.

btm said:

In both cases, the liquid is evaporating from the skin; the latent heat (due to the change of state) absorbed from the hand stop the hand from burning. The blue flame in the hand sanitiser is characteristic of alcohol flames, and you can see it if you set fire to a small amount of metho. If you remove any hairs from the back of your hands (and assuming you have no hair on your palms) you can put some metho on your hands and set fire to it. It also burns with a blue flame, and doesn’t burn you because the alcohol is evaporating.

The NASCAR used to use pure ethanol for their racing cars, trouble was you didn’t know if it was alight or not, you couldn’t see any flames.
I think some drivers got some very bad burns from it but I’ll stand corrected.

btm said:

In both cases, the liquid is evaporating from the skin; the latent heat (due to the change of state) absorbed from the hand stop the hand from burning. The blue flame in the hand sanitiser is characteristic of alcohol flames, and you can see it if you set fire to a small amount of metho. If you remove any hairs from the back of your hands (and assuming you have no hair on your palms) you can put some metho on your hands and set fire to it. It also burns with a blue flame, and doesn’t burn you because the alcohol is evaporating.

Cheers BTM :) I guess these are things I should already know but I’m just going to blame my sleepiness, I’m now working nights.

We generally stay away from fire stuff (though we did burn different materials in the fire while we were camping to create different coloured flames).

I do love the simple things like layer density. We have made slime recently which is very tactile.

Of course the mantis Diet Coke experiment was a blast
And the tea bag rockets is easy quick and nice to watch

The m&m s experiment is tasty.

We tried the mentos & coke one :)

and Skittles in water

I’ll try some of your other suggestions on Sunday :) Thanks!

Arts said:

The m&m s experiment is tasty.

Wot’s dat then?

Witty Rejoinder said:

Arts said:

The m&m s experiment is tasty.

Wot’s dat then?

https://m.youtube.com/watch?v=nj0Id7DN2yY

A suggestion related to your crystal experiment: try dissolving common salt (sodium chloride) in water and growing salt crystals, then compare the shapes of the resultant crystals (salt and sugar), and think about why they’re different and why they’re the shapes they are. Then, if you can get some copper(II) sulphate, grow some crystals of that. Then try dissolving crystals of CuSO₄ and NaCl in the same container of water and crystalise the result, and see what happens, and think about why that happens. If you can’t get CuSO₄, try this last experiment with NaCl and sugar.

For other science experiments that you can do at home, but perhaps shouldn’t, see the book “Mad Science” by Theo Gray. The most famous one from that book is how to make ice cubes that sink.
http://graysci.com

Cheers all :)

I’m curious to know, where one might buy copper sulfate?

JTQ said:

Cheers all :)

I’m curious to know, where one might buy copper sulfate?

Try bunnings.
https://www.bunnings.com.au/manutec-500g-copper-sulphate-soluble_p2961523