Which of the following types of spectra have dark lines?
a. emission spectra
b. absorption spectra
c. continuous spectra
d. noncontinuous spectra

How many hydrogen (h) atoms are in one molecule of sulfuric acid, h2so4? (1 points) 1 2 4 7

Amira pulls a 3 pound wagon 4 feet. how much work has she done?

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.