Which of the following statements is true?
1.since the sun uses its own hydrogen to create energy, it will eventually run out of fuel and burn out.
2.objects in the universe are moving toward earth, which supports the theory that the universe is shrinking.
3.the absolute magnitude of a star measure both luminosity and the stars distance from earth.
4. all the inner planets are less than one au from the sun.

The energy released by a chemical reaction can be measured using a calorimeter. when barium hydroxide octahydrate crystals are reacted with dry ammonium chloride inside of a coffee cup calorimeter, the temperature of the 18.00 g of water in the calorimeter decreases from 30.0°c to 8.0°c. the equation for calculating energy absorbed or released by a reaction is: where q is the energy released or absorbed, m is the mass of water in the calorimeter, cp is the specific heat of water, and δt is the observed temperature change. if the specific heat of liquid water is 4.19 j/g·°c, how much energy was absorbed by the reaction?

What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th

Boiling water is an example of physical change. true or false