Wasim and his friends want to test if the solution of a substance is acidic or not. These are the tests that each of them performed. Wasim: Dipped the blue litmus in the solution Akram: Dipped the red litmus in the solution Neha: Dipped both the blue and the red litmus in the solution one after other. Who among them performed a proper test ?

Achemical reaction (also known as a chemical change) produces substances that are chemically different from the starting materials. an example of a chemical reaction is the formation of water from hydrogen and oxygen gas.in a physical change, a substance changes its physical appearance but not its chemical identity. an example of physical change is the formation of liquid water from solid water, a familiar process called melting. physically, liquid water looks very different from solid water (ice) but the chemical identity, water, is the same for both. which of following changes that affect the composition of our atmosphere involve physical changes and which involve chemical reactions? oxygen gas changes to ozone during thunderstorms carbon dioxide is produced by the combustion of gasoline in an automobile engine. when coal, oil, and natural gas are decomposed in landsills they produce methane gas. freezing rain develops when a warm air mass overrides a cold air mass. fog forms from water vapor when the temperature drops below the dew point

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?

The molar mass of cu is 63.55 g/mol. the number of grams of cu produced in this reaction is