Chemical Equations

In a chemical equation...

• a new substance is formed

• new atoms are formed

• old atoms disappear

• a equal sign is always used

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Reactants are

• new substances

• old substances

• likely to disappear

• likely to appear

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Products are

• old substances

• new substances

• atoms that disappear

• atoms that do not exist

Tags

NGSS.MS-PS1-5

When writing a chemical equation, reactants are on the _____________ while products are on the _________________.

• top, bottom

• right, left

• left, right

• bottom, top

Tags

NGSS.MS-PS1-5

An arrow in a chemical equation means the reaction is irreversible.

• True

• False

A worded equation...

• are detailed

• includes subscripts

• includes coefficients

• uses the full names of the substances

Worded equations provide the amount of each substance in the reaction

• True

• False

Tags

NGSS.MS-PS1-5

In 4H²O, the 4 means...

• There are four water molecules all together

• In every one water molecule, there are four hydrogen atoms

Tags

NGSS.MS-PS1-1

All together there are __________ hydrogen atoms in 4H²O

• 8 hydrogen atoms

• 2 hydrogen atoms

• 4 hydrogen atoms

• 16 hydrogen atoms

Tags

NGSS.MS-PS1-1

The law of conservation of mass states

• chemical reactions create new atoms

• atoms cannot be created or destroyed

• reactants vanish once a reaction takes place

• products appear when a reaction takes place

Tags

NGSS.MS-PS1-5