Uranium-235, uranium-238, and uranium-239 are different

The following chemical equation is balanced: 4 Fe + 3 O 2 ® 2 Fe 2O 3

How many grams of water are produced from 2.5 moles of methane? methane.png

What does Einstein’s energy equation (E = mc 2) say about the energy that is derived from nuclear fission reactions?

This figure shows idealized thermal radiation spectra from several stars and a human. Based on this graph, at about what wavelength does a 15,000 K star emit its most intense light?

What do we mean by the observable universe? 

Which of the following is not a general difference between a planet and a star? 

Tidal friction caused by Earth’s stretching from the Moon’s gravity is gradually slowing down the rotation of Earth. 

Which of the choices below correctly lists things in order from largest to smallest?

The planets never travel in a straight line as they orbit the Sun. According to Newton’s second law of motion, this must mean that