Answer:
D.
Explanation:
She's trying to find the affect different shapes have on the distance the plane flies, not the affect different types of paper have on distance. If she were to use different paper for each plane she'd be testing two variables instead of one.
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Models show systems that are large, small or complex.They make it easy for study through zooming in an area in a large system.They provide visual presentation of an object or a system that has been created through experimental data.
Explanation:
A model is a representation of an idea, a process or an object in a system used by a scientist to describe a phenomenon that is difficult to be experienced directly.The goal of a model is to ensure that the presentation is done in a logical and objective way.
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Keywords : models, scientific research
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C a T ball
Boron's atomic number is 5, so for its 5 protons, it should have 5 electrons if it's neutral.
To make it an ion, Boron's charge would have to be negative or positive. It could lose one electron to have a charge of +1, gain an electron to be -1 ion.
Ions aren't at specific number. So the answer depends on Boron's tendency to gain or lose electrons.
