Week 16 Matter

  Susie wants to make lemonade on a hot summer day. She mixes lemon juice, water, and sugar in a large container. Which of the following happens as she combines the ingredients?

• They mix together to form a new compound. 
• They mix together to form a homogeneous solution
• The stirring motion causes them to break down into elements. 
• The heavier items will not completely dissolve, creating a suspension. 

In the modern periodic table of elements, all of the known elements are arranged by which property?

• radioactivity
• atomic mass
• atomic number
• number of neutrons

Kaitlyn is blending together ingredients to create different mixtures. Which combination of substances would most likely result in a homogeneous mixture?

•  sand and gravel 
• sand and salt
• gravel and water 
• salt and water 

Which of the following statements regarding matter is true?

• Atoms can combine to form compounds.
• The elements make up the building blocks of all matter. 
• Every atom will bond in order to achieve a stable neutron-proton ratio. 
• There are more than 100 naturally occurring elements that make up all matter. 

Which of the following correctly describes a property of an atom?

• It has more protons than neutrons. 
• It has a negative or positive charge. 
• It has an equal number of protons and electrons.
•  It has an equal number of neutrons and electrons. 

Ocean water is a combination of salt and water. Which of the following best describes the composition of ocean water?

• It is an element, since water is found in all living things. 
• It is a suspension, since particles can be found in ocean water. 
• It is a compound, since it results from the combination of elements. 
• It is a solution, since it is made up of one substance dissolved in another.

Walter left his school bag in the car one hot September afternoon while he went into the mall. In it he had his homework paper, six crayons, an empty plastic water bottle, and a chocolate bar. Which of these things is most likely to show the greatest amount of physical change when he returns to the car in an hour?

• homework papaer
• crayons 
• water bottle 
• chocolate bar

Robert is hiking through the forest and writing down his observations. He steps on a branch and it breaks into several pieces. Which of the following best describes the resulting properties of the branch?

• The density of the branch decreased, since it now takes up less space. 
• The molecular arrangement of the branch changed as the broken pieces changed phase. 
• The total mass of the branch pieces is the same, and only a physical change has occurred.
• The chemical composition of the branch changed as the broken pieces reacted with the environment. 

Which of the following is an example of a chemical change?

• freezing water to make ice 
•  boiling water to make steam 
• making salt water from salt and water 
• separating water into hydrogen and oxygen

 Joey is performing an experiment in science class. He mixes two liquids in a test tube, and gas bubbles appear at the surface of the test tube. Which of the following describes what is most likely taking place?

• A physical change is causing a change in phase from liquid to gas. 
• A chemical change has caused the liquids to undergo combustion and gas is escaping.
• A physical change is causing the solution to exhibit different properties than the original substances. 
• A chemical change has resulted in the production of a new substance, which is being given off as a gas.