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The freezing point of bromine is negative seven degrees Celsius, while the freezing point of methane is negative 182 degrees Celsius.
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How much warmer is bromine’s freezing point than methane’s?
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As we want to calculate how much warmer the freezing point is, we know that our answer will be positive.
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We could do this using a number line.
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How can we get from negative 182 to negative seven?
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We could do this by calculating the difference between negative 182 and negative seven.
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Alternatively, we could see that we need to add 182 to get from negative 182 to zero.
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To get from zero back to negative seven, we need to subtract seven.
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This means that to get from negative 182 to negative seven, we need to add 182 and then subtract seven.
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182 minus seven is equal to 175.
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This means that bromine’s freezing point is 175 degrees Celsius warmer than methane’s.
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An alternative method here would be to subtract negative 182 from negative seven.
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We know that subtracting a negative number is the same as adding that number.
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Once again, negative seven plus 182 is equal to 175, confirming that our answer is correct.