L1 Types of Matter

Types of Matter

Chemistry is the study of matter:

Its composition, structure, properties, changes it undergoes, and the energy accompanying these changes.

Matter:

is anything that occupy space and has mass.

Pure substance is a type of matter which every sample has:

definite and fixed composition same unique sets of properties elements and compounds are examples of pure substance

Elements: is a pure substance.

• They are made up of identical atoms. They cannot be decomposed or broken down into simpler substances by physical or chemical methods.

• Example: Au (Gold)

• Ag (Silver)

• Cl₂ (Chlorine gas)

• Br₂ (bromine gas)

Compound is a pure substance that:

• is composed of 2 or more different elements chemically combined.

• has a definite composition (fixed ratio) of all atoms in all samples (Law of definite composition)

• can be decomposed (or broken down) into simpler substance by chemical method

• has a unique set of properties in all samples

• 
  

Compound is a pure substance that:

• is composed of 2 or more different elements chemically combined.

• has a definite composition (fixed ratio) of all atoms in all samples (Law of definite composition)

• can be decomposed (or broken down) into simpler substance by chemical method

• has a unique set of properties in all samples

• 
  

Multiple Select

Which change must occur for HF to form from its elements?

• a physical change

• a chemical change

• a phase change

• a nuclear change

Multiple Select

Which list consists only of substances that can be chemically decomposed?

• K_(s) and KCl_(aq)

• CO _(aq) and CO_{2 (g)}

• Co_(s) and CaCl_2(s)

• LiBr_(s) and CCl_4(l)

Multiple Select

Chemistry is a study of

• composition of matter

• changes in the matter and the energy

• properties of matter

• structure of the matter

• All of the above

Multiple Select

Which list consists only of chemical pure substance?

• soil and water

• air and water

• iron and sodium chloride (salt)

• sugar and concrete

Multiple Select

Matter is defined as

• Anything that mass only

• Anything that has volume only

• Anything that occupy space and mass

• Anything that bothers you matter

Multiple Select

Carbon dioxide, CO₂, is classified as a pure substance because

• its composition can vary

• its composition is fixed

• it cannot be separated

• it can be separated

Multiple Select

Which cannot be decomposed by physical or chemical methods?

• water (H₂O)

• Gold (Au)

• Carbon dioxide (CO₂)

• Sugar (C₂H₁₂O₆)