Electric and Magnetic Forces: Electric Charges

Science Objects are two hour on-line interactive inquiry-based content modules that help teachers better understand the science content they teach. This Science Object is the first of three Science Objects in the Electric and Magnetic Forces SciPack. It explores electric charges and electric force. There are two kinds of charges—positive and negative. The electric force is a universal force that exists between any two charged objects. Like charges repel one another, and opposite charges attract. The strength of the force is directly proportional to the amount of charge, and inversely proportional to the square of the distance between them. On an atomic scale, the nucleus and electrons are the basic constituents of all atoms and create the electric forces that hold atoms and molecules together. On a larger scale, these forces hold solid and liquid materials together and act between objects when they are in contact (for example, friction or the impact of a bat on a ball). In materials, there are almost exactly equal proportions of positive and negative charges, making the materials as a whole electrically neutral. An imbalance in these opposite charges will produce phenomena that range from electric sparks and clinging clothes to lightning.


Elementary SchoolMiddle School


Type Science Object

NSTA Press produces classroom-ready activities, hands-on approaches to inquiry, relevant professional development, the latest scientific education news and research, assessment and standards-based instruction.

Learn More