The emission spectrums are known for the elements below.
What elements are in the unknown sample?check all that apply

Which of the following are guidelines to follow for obtaining accurate observations

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply

The atoms in a nickel crystal vibrate as harmonic oscillators with an angular frequency of 2.3 × 1013 rad/s. the mass of a nickel atom is 9.75 × 10-26 kg. what is the difference in energy between adjacent vibrational energy levels of nickel? (h = 6.626 × 10-34 j • s, , 1 ev = 1.60 × 10-19 j)