HELP PLEASE WILL GIVE BRAINLIEST! Find the mass of an object that has a density of 1.5 g/cm^3 and has a volume of 8 cm^3

Scientists use laser range-finding to measure the distance to the moon with great accuracy. a brief laser pulse is fired at the moon, then the time interval is measured until the "echo" is seen by a telescope. a laser beam spreads out as it travels because it diffracts through a circular exit as it leaves the laser. in order for the reflected light to be bright enough to detect, the laser spot on the moon must be no more than 1.0 km in diameter. staying within this diameter is accomplished by using a special large-diameter laser. part a if λ = 540nm , what is the minimum diameter of the circular opening from which the laser beam emerges? the earth-moon distance is 384,000 km. express your answer to two significant figures and include the appropriate units.

True or false: the cycle of seasons on the earth is caused by the tilt of the earth on its axis toward and away from the sun.

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?