Is car wax a mixture compound or a solution

Classify this reaction: 2al+n2-> aln.

Ascientist measures the speed of sound in a monatomic gas to be 449 m/s at 20∘c. what is the molar mass of this gas?

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)