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Water + Hydrogen
Moderators: AmyCowen, kgudger, bfinio, MadelineB, Moderators
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deleted-43434
- Posts: 1
- Joined: Fri Aug 02, 2013 4:57 pm
- Occupation: student 7th grade
- Project Question: Study of the content of water in objects.
- Project Due Date: Feb. 2014
- Project Status: I am just starting
Water + Hydrogen
Why is it that oxygen which is a light molecule becomes heavier when you add two hydrogen molecules? I am confussed by this.
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deleted-137222
- Posts: 15
- Joined: Fri Jun 21, 2013 9:37 am
- Occupation: Student, 8th Grade
- Project Question: Microbial Fuel Cells
- Project Due Date: Spring 2014
- Project Status: I am just starting
Re: Water + Hydrogen
Hi Cora,
When you look at the numbers under the elements on the periodic table, you see that the mass of oxygen is 16. Compared to say, lead, which has a mass of 207.2, oxygen is a pretty light element. On the other hand, look at the mass of hydrogen. It's the lightest of all elements at just 1.008. Oxygen is a lot heavier than hydrogen. Whenever you combine atoms into a compound, and in this case it's water, you add up all the elements in the chemical formula. Since the chemical formula of water is H2O, you add the mass of two hydrogens and one oxygen. 2(1.008) + 16 = 18.016. Therefore, even though there's two hydrogens, oxygen still makes up a big part of water.
When you look at the numbers under the elements on the periodic table, you see that the mass of oxygen is 16. Compared to say, lead, which has a mass of 207.2, oxygen is a pretty light element. On the other hand, look at the mass of hydrogen. It's the lightest of all elements at just 1.008. Oxygen is a lot heavier than hydrogen. Whenever you combine atoms into a compound, and in this case it's water, you add up all the elements in the chemical formula. Since the chemical formula of water is H2O, you add the mass of two hydrogens and one oxygen. 2(1.008) + 16 = 18.016. Therefore, even though there's two hydrogens, oxygen still makes up a big part of water.