Which of the following is an example of a physical change?

a. a piece of iron being heated until it melts

b. silver jewelry tarnishing

c. a piece of wood burning

Which is the most likely way an automotive engineer would use chemistry

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?

What is the compound name for the formula [ru(en)2cl2]2+ and [co(en)cl2br]-