Define couple and give 2 examples

Which of the following represents an upright image? a. -do b. +m c. -m d. +do

True or false when elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it.

Photoelectrons with a maximum speed of 6.50 x 107 m/s are ejected from a surface in the presence of light with a frequency of 6.75 x 1014hz. if the mass of an electron is 9.10 x 10-31 kg, calculate in joules the maximum kinetic energy of a single electron. 3.84 x 10-15 j 1.92 x 10-15 j 5.92 x 10-23 j 3.07 x 10-16 j