Which of these mixtures are heterogeneous? 1.brass (an alloy of copper and zinc) 2.granite (a type of rock with multicolor spots) 3.oil and water 4.salt and water

Acontrol during an experiment. might change remains constant does not exist does change

The atomic number, or number, is the described as the number of in the nucleus of an chemical element.

Scientists often have to deal with numbers that are either very large or very small. for example, the radius of the sun is approximately 696,000 kilometers, while bacterial cells are as small as 1.9 × 10-4 millimeters. express each number in an alternate form.