Answer:
When a light bulb connects to an electrical power supply, an electrical current flows from one metal contact to the other. As the current travels through the wires and the filament, the filament heats up to the point where it begins to emit photons, which are small packets of visible light.
Explanation:
science
Answer:
<h2>Answer⤵</h2><h3><u>The number in a mole, Avogadro's number, is related to the relative sizes of the atomic mass unit and gram mass units. Whereas one hydrogen atom has a mass of approximately 1 u, 1 mol of H atoms has a mass of approximately 1 gram.</u></h3>
Answer:
Is the atomic theory known, for certain, to be true?
Answer:
No; a theory, as all scientific principles, is never certain. It is permanently subject to testing and experimental verification. Even if a theory is found to agree with all of the available observational data, and all of its predictions have been found to be ``correct'', i.e. borne out by all observations until today, it may yet be disproved by tomorrow's more precise observations. It is, in fact, the attempt to disprove the existing theories which is the purpose of most scientific experimentation.
[2.2]
Carbon atoms are about 25% lighter than oxygen atoms (the ratio of their weights is 3 to 4). What is the weight ratio of the carbon and oxygen that go into the formation of carbon monoxide? Answer the same question for carbon dioxide.
Answer:
Carbon monxyde has the chemical composition CO, i.e. there is one carbon atom for every oxygen atom; therefore the weight ratio of carbon to oxygen in this compound is just the weight ratio of the atoms, i.e. 3 to 4. In carbon dioxide, tex2html_wrap_inline121 , there are two oxyen atoms per carbon atom, so the carbon to oxygen weight ratio in carbon dioxide is 3 to 8.
[2.4]
Which of these is a pure compound, which is an element, and which is neither: (a) pure water, (b) oxygen gas, (c) liquid mercury, (d) tex2html_wrap_inline123 , (e) U, (f) air,
(g) He, (h) carbon dioxide, (i) tex2html_wrap_inline125 , (j) polluted water?
Answer:
Explanation:
hope it help ;)
So, negatives are tricky. But here's a nice rule for it:
1). negative (-) times negative (-) is positive because like signs, when multiplied are always positive.
2). negative (-) times positive (+) is negative because, different signs, when multiplied, are always negative.
3). positive (+) times positive (+) is positive because, again, like signs, when multiplied, are always positive.
Let's do the first 2 together:
So -5 times 7. First, let's ignore the signs and do the numbers first. 5 * 7 = 35. Cool. Now lets do the signs. Since it's a negative times a positive, it'll be negative. So your answer is -35.
Now lets do -8 times -4. Ignore the signs. 8 * 4 = 32. Now the signs. It's negative times negative. So it'll be positive because like signs, when multiplied, will always be positive. So the answer to the second one is 32.
Hope this helps!!