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11 Cards in this Set
- Front
- Back
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What is an Endothermic reaction |
Reactions that take in energy from the surroudings |
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What is an Exothemic reaction |
Reactions that transfer energy to the surroundings |
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Who was John Newland and what did he do? |
He created the first periodic table |
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How many elements had been discovered by 1864? |
Around 60 elements had been discovered by 1864 |
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What were the problems with Newlands table of Octaves? |
-Many of the atomic weights he used were not accurate -Some of his 'elements' were actually mixtures -He did not leave room for undiscovered elements -He often put 2 elements in the same box when convenient
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Who published a new periodic table in 1869? |
Dmitri Mendeleev |
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What were 2 benifits of having Mendeleevs periodic table? |
-He recalculated the wrong atomic weights on Newlands table of Octaves -He lined up the elements with similar properties |
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Define the word Element |
An element is a substance formed of atoms which all have the same number of protons |
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Define the word Mixture |
A mixture is 2 or more elements mixed together (e.g paint) |
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Define the word Compound |
A compound is 2 or more elements chemicaly bonded together |
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What is the trend in melting points as you go down the group 1 elements? |
They get higher |
