How are metallic bonds formed? a) valence electrons are transferred between atoms. b) valence electrons are shared between two atoms c) valence electrons are shared among many atoms creating a "sea of electrons". d) valence electrons are gained or lost, creating ions that are held together by opposite charges.

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.

Zeros that follow non-zeros numbers and are also to the right of a decimal point are significant

What is the rate of change in a objects position?