A carpenter sands a wooden board until it is smooth. Is this a physical or a chemical change?

Which one of the following statements about sulfric acid is correct? A. Sulfric acid is a known muriatic acid B. Sulfric acid has little effects on metals C. Sulfric acid is dangerous to living organisms D. Sulfric acid is a strong oxidizing agent

Which diagram best illustrates what happens when electromagnetic waves strike a reflective material? A horizontal red curved line passes across a vertical black line labeled surface turning up as it crosses the black line.

Light travels 300,000,000 m/s, and one year has approximately 32,000,000 seconds. A light year is the distance light travels in one year. State the speed in m/s, using scientific notation.

The prediction of the outcome of scientific processes based on analysis.

When the source of a sound is moving it's speed increases

What two controls on a car causes a change in speed

What is the total resistance of the circuit shown below?

As a clinical chemist in charge of the testing of blood samples. You are required to mix a solution of sodium chloride with water in the ratio of 2:5.

A positively charged object will attract an object that has A. a negative charge B. a smaller positive charge C. no charge D. a larger positive charge

Whats the usefulness or inconvenience of frictional force by turning a door knob?