Which of the following is a good example of a contact force?

a. earth revolving around the sun
b. a bridge suspended by cables
c. a ball falling downward a few seconds after being thrown upward
d. electrically charged hairs on your head repelling each other and standing up

Arollercoaster car at the top of a hill has potential energy kinetic energy chemical energy light energy

The alkali metals (group 1) consist of lithium (3), sodium (11), potassium (19), rubidium (37), cesium (55), and francium (87). they are soft, metallic solids with low densities and low melting points. based on the data shown in figure 1, how many valence electrons do alkali metals share?

Indicate whether the specified alkyl halides will form primarily substitution products, only elimination products, both substitution and elimination products, or no products when they react with sodium methoxide. 1-bromobutane 1-bromo-2-methylpropane 2-bromobutane 2-bromo-2-methylpropane