What are the indications/signs that a chemical change has occurred?

What is the difference between atom and compound? explain.

A piece of sodium metal reacts completely with water to produce sodium hydroxide and hydrogen gas. the hydrogen gas generated is collected over water at 25.0 degrees celsius. the volume of the gas is 246 ml measured at 1.00 atm.

Wich is not a characteristic common to all minerals

How many photons are contained in a burst of yellow light (589 nm) from a sodium lamp that contains 623 kJ of energy?

Which part of the organ of the digestive system absorbs nutrients from digested food

Is a gas that is produced by the ultraviolet radiation in the air in the vicinity of welding operations?

How much MnO2 (s) should be added to excess HCl (aq) to obtain 295 mL of Cl2 (g) at 25 °C and 735 Torr?

Why do people describe water as a universal solvent

What is litmus paper used for? To indicate if all the reactants have been used up to determine if a chemical reaction has occurred to determine pH to detect the presence of water

You open your lemonade stand with 100 lemons, 5 bags of sugar containing 6 cups each, and 10 gallons of water (16 cups per gallon). Which statement is NOT true about the production of lemonade in your stand?