the guy

ah, thank you, that's made it clear now, i shall try and remember in future too!

I tried that, and got two different areas... and yes i know there is but this isn't homework...

I'm trying to construct something and i have confused myself, I can't remember my maths lessons! So I'm stuck on how to work something out... If there are two circles, one within the other (lets call the outer circle 'O' and the inner circle 'I'), If circle I has a radius of 2cm, What should the radius of O be, so that the area of I is equal to the area of O - I? your help would be very, well, helpful! thanks in advance

what ratio of CaO:H2O should I use to get the maximum amount of heat?

ah thank-you and because i am making something which requires an exothermic reaction between two substances, which i have purchased calcium oxide for, intending to use it with water, but it occurred to me that hydrogen peroxide might react more. however, i cannot have gases being released in in this application, so it won't be useful. thank you kindly for your answer it was helpful

oh i see, well i was told they were AC. the ones that produce a constant buzzy sensation. not the instant shock ones, which are piezoelectric and so are DC.

does calcium hydroxide react with hydrogen peroxide? if so, what are the reactants? and does is give off heat (like when it reacts with water)? if so, is it more or less heat than in the reaction with water?

can hormones be taken orally or absorbed under the tongue?

does anyone know (or have an educated guess) what frequency electric shock pens operate at?

does anyone know (or have an educated guess) what frequency electric shock pens operate at?

Ah, thank-you, i was just curious, i had sudden wild flashes of inventing a new form of blasting cap or something, before realizing that it would probably be ridiculously expensive, and now realizing that it wouldn't work anyway. Oh well. And don't worry i have no intention of foolishly blowing bubbles into nitroglycerine! thanks for your answer

theoretically, could sonication be used as a method of detonation? i was just thinking cause i know detonation has something to do with shock waves and such and such and, when reading about sonication and sonochemistry i noticed this: 'sonochemistry arises from acoustic cavitation: the formation, growth, and implosive collapse of bubbles in a liquid.' i was just wondering if this would have a detonating effect on high-explosive liquids...?

hi, i'm trying to build something electronic but, unfortunately, my knowledge of electronics is naff and i am getting incredibly blagged and confused trying to figure out how to do this on the internet. what i am attempting to do is create a circuit which converts a 4.5v DC power supply to a 50Hz 39v AC power supply. if you could provide simple instructions on how to achieve this i would be most grateful. (by simple i mean the names and specifications of the components i need and how to connect them. nothing more, nothing less, otherwise i will get confused xD) your help would be much appreciated, thanks.

for an experiment with the exothermic reaction with water. and yeah i had considered that but wanted to check if there was an easier way first.

i think that's hydrated lime =/

where can i buy calcium oxide powder? thanks in advance to any replies

is it possible for a virus to have two different types of receptor-binding protein and so be able to infect two different types of cell?

if you added water and then let plaster of paris set, then immersed it in sodium carbonate solution, would it convert to calcium carbonate? if so, would the CaCO3 be on the surface, all the way through, or in small particles in suspension? *the set plaster of paris being hydrated calcium sulfate of course

does that mean yes?

would aluminium powder ignite if you put it in a microwave oven?

is calcium carbonate a sustainable resource?

ah ok thankyou

would i be able to dissolve calcium chloride in ammonia solution, in order to get a solution of ammonia and calcium chloride, or would the calcium chloride react with the ammonia solution and leave me with different products?

in the experiment in which sodium alginate is dripped into calcium chloride solution to create little beads, if you leave the beads in the solution for long enough, will they solidify all the way through, or will they stay liquid in the centre?

can photokeratitis (aka welder's flash, snowblindness, arc eye etc.) cause permanent blindness if exposure and intensity of the UV are strong enough?