Which of these has the most impact on the apparent brightness of a star seen from Earth? Gravitational pull, temperature of star, distance from earth, earths orbital pattern

Discuss the characteristics of an open, closed, and isolated system

According to the bohr model of the atom, which electron transition would correspond to the shortest wavelength line in the visible emission spectra for hydrogen? hints

Anything that melts is it a chemical change?

Normal cellular pH has a hydrogen concentration of 3.98 x 10-8 M. what is the pH of a cell

Name 5 elements that we don't know what the state is at room temperature

Which statement describes the redox reaction that occurs when an object is electroplated? A. It is spontaneous and requires an electric current. B. It is spontaneous and produces an electric current. C.

How are electromagnetic different than all other waves

Find the ratio of speeds of an electron and a negative hydrogen ion (one having an extra electron) accelerated through the same voltage, assuming non-relativistic final speeds. Take the mass of the hydrogen ion to be 1.67*10^{-27} kg.

A type of rock that undergoes changes because of heat and pressure

How many milliliters of a 1.25 molar HCL solution would be needed to react completely with 60 g of calcium metal Ca+2HCl - - > CaCl2 + H2