What can you determine about an element if you only know its group number on the periodic table?
A. The number of valance electrons
B. The total number of protons and neutrons
C. The number of protons
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D. The total number of electrons

1. baking powder is a 1: 1 molar mixture of cream of tartar (khc4h4o6) and baking soda (nahco3). a recipe calls for two teaspoons (a total of 8.0 grams) of cream of tartar. how much baking soda must be added for both materials to react completely?

Write the chemical symbols for three different atoms or atomic cations with 27 electrons. asap!

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