What can you observe to know that when clear methane gas is burned it is a chemical change?

1)change of color
2) formation of a precipitate
3) change in mass
4) formation of a gas
5) change in temperature
6) change in shape

Acar travels along a highway with a velocity of 24 m/s, west. the car exits the highway; and 4.0 s later, its instantaneous velocity is 16 m/s, 45° north of west. what is the magnitude of the average acceleration of the car during the four-second interval?

Examine the equation. 23490th→23088ra+42he what kind of barrier would you need to block the radioactive particles from this reaction? a.a piece of paper b.a sheet of aluminum foil c. a two-inch block of lead d. a solid concrete block

Why should seat belts not be mandatory quick plz