Which of these is an example of a physical change?

a banana ripening in the air

hydrogen burning in the air

zinc reacting with an acid

liquid water turning into vapor

A new concept that is tested in a scientific investigation is known as

Acids react with metals to produce A. water and a salt B. Hydrogen gas C. A base

Which of the following is a pure substance? A. oxygen B. air C. salt water D. maple syrup

Give the number of protons and electrons in each of these ions or atoms (show your work) Cs. Ba,. s

Why is HBrO a weak acid

A chemist determined by measurements that 0.050 moles of aluminum participated in a chemical reaction. Calculate the mass of aluminum that participated in the chemical reaction. Be sure your answer has the correct number of significant digits.

In 1901, Thomas Edison invented the nickel-iron battery. The following reaction takes place in the battery. Fe (s) + 2 NiO (OH) (s) + 2 H2O (l) Fe (OH) 2 (s) + 2 Ni (OH) 2 (aq) How many mole of Fe (OH) 2, is produced when 5.35 mol Fe and 7.

As you move from left to right across the periodic table, the atomic numbers increase decrease stay the same are random

Use the octet rule to predict the formula of the compound that would form between fluorine and iodine, if the molecule contains only one fluorine atom and only single bonds are formed.

64.0 grams of Sulfur Dioxide absorbed 5.00 kJ of heat and immediately evaporated. With this information, calculate its molar enthalpy of vaporization in units kJ/mol.