How is a pure substance different from a mixture? a: a pure substance is heterogeneous b: a mixture is made of one substance c: mixtures cannot be separated by physical means d: pure substances cannot be separted by physical means

Is this a single replacement reaction or there is no

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

In the cathode ray tube experiment, j. j. thomson passed an electric current through different gases inside a cathode ray tube in the presence of an electric field. in which two ways did this experiment change scientists’ understanding of the atom?