Melting, boiling, anf bending are physical changes but why is burning a chemical change

Classify which of the following is a substance: tablero salt, seawater or sand? Explain how you know.

What is the total energy of all the particles in an object? endothermic energy exothermic energy thermal energy temperature

if a star 100 light years from earth is beginning to expand into a giant star how long will it take for astronomers to observe this development explain

What is the dimension of ment of inertia?

Two skaters, a man and a woman, are standing on ice. Neglect any friction between the skate blades and the ice. The mass of the man is 95 kg, and the mass of the woman is 51 kg. The woman pushes on the man with a force of 60 N due east.

What is it called when you connect an object to earth with a conductor

Why is venus the hottest planet in the solar system

Which of the following is an example of an electromagnetic wave? A. ripples on a lake B. the honking of a car horn C. the light from a neon sign D. aftershocks from an earthquake

How fast can we travel in space with current technology?

How would the tides on earth be different if the moon revolved around the earth in 15 days instead of 30 days