Which option is an example of a physical change? iron rusting
metal denting
silver tarnishing
gasoline burning

please hurry
Brainliest if right!

What semimetal can form four single covalent bonds.

Cryolite, na3alf6(s), an ore used in the production of aluminum, can be synthesized using aluminum oxide. start this question by first balance the chemical equation.1.) balance the equation: - alo3(s)+naoh(l)+hf(> na3alf6+h2o(g). 2.) if 17.5 kilograms of al2o3(s), 51.4 kilograms of naoh(l), and 51.4 kilograms of hf(g) react completely, how many kilograms of cryolite will be produced? 3.)which reactants will be in excess, (al2o3, naoh, or hf) 4.)what is the total mass of the excess reactants left over after the reaction is complete in kg?

There are approximately 15 milliliters (ml) in 1 tablespoon (tbsp). what expression can be used to find the approximate number of milliliters in 3 tbsp?