A system in which No matter or energy can enter or exit from the surroundings

(matter and energy cannot enter or exit).

What elements are stars mostly made of? How do we know this?

Which type of electromagnetic ave is the highest in frequency

During a solar eclipse the Moon is positioned directly between Earth and the Sun. Find the magnitude of the net gravitational force acting on the Moon then, due to both Earth and the Sun. The masses of the Sun, Earth, and the Moon are 1.

Why does an ice cube feel cold when you touch it?

Force equals blank times acceleration

17. (a) Will the electric field strength between two parallel conducting plates exceed the breakdown strength for air (3.0*106 V/m) if the plates are separated by 2.00 mm and 5.

What property of sound enables us to distinguish one sound source from another?

The table below shows the right ascensions of two stars at a location. Star 1 - 4 right ascension (in Hour) Star 2 - 3 right ascension (in Hour) Which of these statements is correct about the stars?

H-2 + H-3 → He-4 + Consider the nuclear reaction that takes place in the sun. Two nuclides of hydrogen fuse to form helium. Is helium the only product of this reaction? If no, identify any additional products. A) Yes, He-4 is the only product. B) No.

Hat is a scientific theory? Make up your own scientific theory.