-
Asked by poisen2 to Adam, Catherine, Karen, Leila, Nazim on 13 Mar 2012.
-
Catherine Rix answered on 10 Mar 2012:
It depends what kind of atom it is. A hydrogen atom weighs 0.00000000000000000000000000016 kg (I think I’ve got the number of zeros right!). You would need to take more than 600000000000000000000000 hydrogen atoms to get 1g of hydrogen! Hydrogen is the lightest atom, but it nature you would find molecules of hydrogen, where two hydrogens join together, rather than atoms of hydrogen making it twice as heavy.
-
-
Adam Stevens answered on 10 Mar 2012:
Atoms are all made up of protons, neutrons and electrons. Electrons have a very small mass compared to the other two so we generally don’t count them. If you know the number of protons and neutrons in the atom you can work out its mass, by adding them up.
But actually, if you do this and measure very accurately the mass of the atom (which we can do), you get a different results! This then starts to get into very complicated nuclear physics, but it’s really interesting because the difference between the calculated mass and the real mass is where the energy from nuclear reactions comes from!
-
Leila Battison answered on 10 Mar 2012:
An atom is so unbelievably ridiculously tiny, that its not easy to put it on a scales and measure its weight directly, so you need to do a bit of sneaky maths and chemistry to get around the problem.
You can get to Catherine’s answer by dividing the average atomic weight (that’s roughly the number of protons and neutrons in the atom added together, like Adam said!) by ‘Avogadro’s Number’, which is about 602,200,000,000,000,000,000,000 (just over 6 trillion trillion), to give you the answer in grams.
So an atom oxygen, which has an atomic weight of 16 (eight protons and eight neutrons), will actually have a mass of about 0.000000000000000000000027 grams – over 10 times heavier than an hydrogen atom.
-
Nazim Bharmal answered on 10 Mar 2012:
Imagine breathing in really deep. The air you’ve put inside yourself is made up of lots of atoms, but it weighs only about as much as 4 grains of sugar. (Which is why it doesn’t matter if you breath in or out when you get on weighing scales.)
Okay, but how many atoms in that air you breathed in? Well, if you take one bag of sugar you have about 8 million grains of sugar. (I don’t have to count, we can estimate it accurately using special magic we are taught …just kidding, we can just use physics.) Now, if we take lots of sugar and fill every football stadium in England, we still don’t have enough grains of sugar.
In fact, you would have to fill 2000 football stadiums full of sugar to get the same number grains of sugar as number of atoms in the air that you breathed in! Imagine how heavy that sugar would be. That is why the mass of an atom is so tiny, like Catherine and Leila said.
(ps I would fill the Emirates Stadium full of sugar, but not White Hart Lane…)
-
Karen Masters answered on 13 Mar 2012:
1 atomic mass! 😉 You can Google the answer in different units. It’s very tiny – there are a lot of atoms in even the smallest thing you can imagine being able to see.
Comments