Distinguishing Physical and Chemical Changes

What remains unchanged in a physical change?

• The chemical composition

• The physical appearance

• The phase of matter

• The temperature

Which example illustrates a physical change?

• Burning wood

• Dissolving salt in water

• Cooking an egg

• Rusting of iron

Tags

NGSS.MS-PS1-4

What is a key characteristic of a chemical change?

• No new substances formed

• Physical properties remain

• Easily reversible

• Formation of new substances

Tags

NGSS.MS-PS1-2

What happens to the proteins in an egg when cooked?

• They are denatured

• They are frozen

• They are dehydrated

• They are dissolved

In a chemical equation, what are the substances on the left side called?

• Coefficients

• Catalysts

• Reactants

• Products

What does the 's' in parentheses indicate in a chemical equation?

• Supercooled

• Solid

• Solution

• Suspended

Tags

NGSS.MS-PS1-4

What role do coefficients play in a chemical equation?

• Indicate the phase of compounds

• Show the temperature conditions

• Determine the speed of the reaction

• Represent the number of molecules

Tags

NGSS.MS-PS1-1

According to the law of conservation of mass, what must remain constant in a chemical reaction?

• Total mass

• Number of products

• Volume of reactants

• Energy levels

Tags

NGSS.MS-PS1-5

What indicates an unbalanced chemical equation?

• Same number of molecules on both sides

• Equal number of reactants and products

• Different mass on reactant and product sides

• Equal mass on both sides

Tags

NGSS.MS-PS1-5

What is necessary to balance a chemical equation?

• Adjusting the temperature

• Changing the reactants

• Using correct coefficients

• Altering the products

Tags

NGSS.MS-PS1-5