Sem 1 Final Exam Physical Science Review 2425 English

Front

What are coefficients in a chemical equation?

Back

Coefficients are the numbers placed in front of the compounds in a chemical equation to indicate the number of molecules or moles of that substance involved in the reaction.

Front

What is the significance of subscripts in a chemical formula?

Back

Subscripts indicate the number of atoms of each element in a molecule. For example, in H2O, the '2' indicates there are two hydrogen atoms.

Front

What is a phase change?

Back

A phase change is a transition of matter from one state to another, such as solid to liquid (melting) or liquid to gas (evaporation). All phase changes require energy to be added or removed.

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What family does Magnesium (Mg) belong to?

Back

Magnesium belongs to the alkaline earth metals family.

Front

What is the atomic number of Barium (Ba)?

Back

The atomic number of Barium is 56.

Front

How do you balance a chemical equation?

Back

To balance a chemical equation, adjust the coefficients of the reactants and products to ensure that the number of atoms for each element is the same on both sides of the equation.

Front

What is the difference between a reactant and a product in a chemical reaction?

Back

Reactants are the starting substances in a chemical reaction, while products are the substances formed as a result of the reaction.

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; the total mass of reactants equals the total mass of products.

Front

What is an example of an endothermic reaction?

Back

An example of an endothermic reaction is the process of photosynthesis, where plants absorb energy from sunlight.