Which of these stars has the hottest core? (a) a white main-sequence star (b) an orange main-sequence star (c) a red main-sequence star

How can two machines appear identical and yet not have the same actual mechanical advantage

What is The definition of Ptolemy

Which is the best term to describe a chemical reaction in which the reactants have more potential energy than the products? A. Thermal conductor B. Endothermic C. Exothermic D. Thermal insulator

10 What produces electromagnetic radiation?

Which of the following quantities is a vector in character? electric energy electric potential difference electric charge electric field

A small cylinder made of a diamagnetic material is brought near a bar magnet. One end of the cylinder is brought near the North pole of the magnet and is repelled.

Which of the following is true about rows of the periodic table? Atomic mass increases from left to right.

Which of these atoms is most likely to share electrons with other atoms?

A rapidly moving cold air mass meets a slowly moving warm air mass and forms a front. what will most likely occur at this front?

It is believed that during the late Cretaceous period sea levels rose drastically resulting in about a third of the Earth's present land masses being underwater. Which of the following types of evidence supports this theory? A.