What does the Law of Conservation of Mass state?

• Matter is created and destroyed in a chemical reaction.

• Matter is neither created nor destroyed, just transferred.

• Matter is only destroyed in a chemical reaction.

• Matter can be transformed into energy.

Tags

NGSS.MS-PS1-5

When balancing chemical equations, what is the first step?

• Balance the most complex molecule.

• Sum all the atoms and make a chart.

• Guess and check the coefficients.

• Balance the hydrogen atoms first.

Tags

NGSS.MS-PS1-5

What does balancing a chemical equation involve?

• Changing the chemical formulas of the reactants and products.

• Adding coefficients to ensure the number of atoms of each element is equal on both sides.

• Removing elements to simplify the equation.

• Increasing the temperature of the reaction.

Tags

NGSS.MS-PS1-5

What should be true for all elements in a balanced chemical equation?

• They should all be gases.

• They should react with each other.

• They should be equal and as simplified as possible.

• They should be in their elemental form.

Tags

NGSS.MS-PS1-5

What is the purpose of making a chart when balancing chemical equations?

• To list the physical properties of each element.

• To track the number of atoms of each element.

• To determine the temperature of the reaction.

• To identify the catalysts in the reaction.

Tags

NGSS.MS-PS1-5

What is meant by ‘balancing’ in the context of chemical equations?

• Ensuring the equation is symmetrical.

• Making sure the physical states of all reactants and products are mentioned.

• Ensuring the number of atoms for each element is the same on both sides of the equation.

• Confirming that the reaction is exothermic.

Tags

NGSS.MS-PS1-5

What role do coefficients play in balancing chemical equations?

• They indicate the temperature at which the reaction occurs.

• They change the chemical properties of the substances involved.

• They represent the number of molecules of each substance.

• They show the speed of the chemical reaction.

Tags

NGSS.MS-PS1-5

What is typically the first element balanced in a chemical equation?

• The element with the least atoms.

• The element with the most complex structure.

• Any random element.

• An element chosen based on its position in the periodic table.

Tags

NGSS.MS-PS1-5

Why might balancing chemical equations involve some trial and error?

• Because the exact composition of substances is unknown.

• Due to the unpredictability of chemical reactions.

• Because finding the correct coefficients may require adjustment.

• Because the laws of chemistry are not always consistent.

Tags

NGSS.MS-PS1-5

In a balanced chemical equation, what happens to atoms from the beginning to the end of the reaction?

• They change into different atoms.

• They are destroyed and then recreated.

• They remain the same, just rearranged.

• They are converted into energy.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5