What does the atomic number tell us about an atom of a certain element?

Which value is equivalent to 178 centimeters? a. 1.78 millimeters b. 17.8 millimeters c. 1.78 meters d. 1.78 * 10-2 micrometers e. 1.78 * 10-5 kilometers

Who is the greek philisopher who came up with the idea that atoms exist

A pair of eyeglass frames is made of epoxy plastic. At room temperature (20.0°C), the frames have circular lens holes 2.50 cm in radius. To what temperature must the frames be heated if lenses 2.

2. Two cars A and B are heading forward. The velocity of A and B are 30 m/s and 20 m/s respectively. If their masses are same as 9.

A football is thrown toward a receiver with an initial speed of 16.9 m/sat an angle of 36.5◦ above the horizontal. At that instant, the receiver is 16.8 m from the quarterback. The acceleration of gravity is 9.81 m/s2.

The scientific method begins with recognizing a problem. The recognized problem in this scenario is, "Why is the printer in the office not working?" Choose the hypotheses that are testable and from which an experiment can be formed.

The correctly balanced equation for H2O2 → H2O + O2 is

How would an unbalanced chemical equation convey misleading information about what took place during a chemical reaction?

A car rounds a 75-m radius curve at a constant speed of 18 m/s. a ball is suspended by a string from the ceiling the car and moves with the car. the angle between the string and the vertical is:

Emission of light from an atom occurs when an electron