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Name: Eva Karen McInnis
Status: student
Age: 10
Location: N/A
Country: N/A
Date: 1999

Why does a dome form on a coin when you pipette water on it drop by drop?

Water is a polar molecule-that is it has a negatively charged end and a positively charged end. The negative end of one water is attracted to the positive end of another and they stick together tightly. So when you drop water on a coin the molecules of water in the new drop stick to the water droplets in the old drops until gravity overcomes the electric forces. How many drops can YOU pile on a coin before it spills over?

K. VanHoeck

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