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 chemically bond together in a fixed ratio.

Front

How many elements are in the chemical formula NaCl?

Back

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

Front

How many hydrogen atoms are in the chemical formula CH₄?

Back

There are 4 hydrogen atoms in the chemical formula CH₄.

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 total number of atoms in the chemical formula NaCl?

Back

The total number of atoms in the chemical formula NaCl is 2 (1 sodium atom and 1 chlorine atom).

Front

What distinguishes elements from compounds?

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Elements are made up of the same type of atoms, while compounds are made up of different types of atoms.

Front

What is the significance of the periodic table in chemistry?

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The periodic table organizes all known elements based on their atomic number, electron configuration, and recurring chemical properties.

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.

Front

What does the subscript in a chemical formula indicate?

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The subscript in a chemical formula indicates the number of atoms of the element that are present in the molecule.