7th Unit 1 Counting atoms

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. Each element is made up of atoms that have the same number of protons.

Front

How do you determine the number of different elements in a chemical formula?

Back

Count the unique symbols in the formula. Each symbol represents a different element.

Front

What does the subscript in a chemical formula indicate?

Back

A subscript indicates the number of atoms of the element that are present in the molecule. For example, in H2O, the '2' indicates there are two hydrogen atoms.

Front

What is the molecular formula for glucose?

Back

C6H12O6

Front

How many total atoms are in the molecular formula C6H12O6?

Back

24 atoms (6 Carbon + 12 Hydrogen + 6 Oxygen = 24 total atoms).

Front

What is the significance of coefficients in a chemical equation?

Back

Coefficients indicate the number of molecules or moles of a substance involved in a reaction.

Front

How many hydrogen atoms are in the compound C8H10N4O2?

Back

10 hydrogen atoms.

Front

What is the formula to calculate the total number of atoms in a compound?

Back

Add the number of atoms of each element present in the molecular formula.

Front

In the compound H3O5CaCl7, how many calcium atoms are present?

Back

1 calcium atom.

Front

What is the difference between a compound and a mixture?

Back

A compound is a substance formed when two or more elements chemically bond together, while a mixture is a combination of two or more substances that retain their individual properties.