Select the correct answer. Galileo was the first scientist to do which of the following?
A. estimate the speed of light
B. propose the heliocentric theory
C. discover radioactivity
D. define and measure speed
E. invent the reflecting telescope​

Which statement best describes how private industry decides where to spend the money on research and development

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?