Elements and Compounds Flashcard

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. It consists of only one type of atom.

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together. For example, water (H2O) is a compound made of hydrogen and oxygen.

Front

How many elements are in the chemical formula C6H12O6?

Back

There are 3 different elements: Carbon (C), Hydrogen (H), and Oxygen (O).

Front

What does the subscript in a chemical formula indicate?

Back

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

Front

How many hydrogen atoms are in the chemical formula CH4?

Back

There are 4 hydrogen atoms in the chemical formula CH4.

Front

What is the total number of atoms in the chemical formula NaCl?

Back

There are 2 atoms in the chemical formula NaCl: 1 sodium (Na) atom and 1 chlorine (Cl) atom.

Front

Which of the following is a compound: O2, H2O, N2, He?

Back

H2O is a compound because it consists of two different elements: hydrogen and oxygen.

Front

How many oxygen atoms are in the chemical formula CO2?

Back

There are 2 oxygen atoms in the chemical formula CO2.

Front

What is the difference between an element and a compound?

Back

An element is made of one type of atom, while a compound is made of two or more different types of atoms chemically bonded together.

Front

What is a chemical formula?

Back

A chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound.