Chemical and Physical Changes

If a substance is composed of one type of atom that is arranged in one particular way, how is this substance best classified

• element

• compound

• mixture

• gas

In the current model of the Periodic Table of Elements, the elements have been placed in groups or families. Why have the elements been organized in such a way?

• Elements in each group have similar densities.

• Elements in each group all have similar boiling points.

• Elements in each group have similar physical and chemical properties.

• Elements in each group have the ability to chemically react with the other elements within that group.

A science teacher mixes calcium chloride and vinegar in a test tube. He passes the test tube around for his students to feel. The students notice that the test tube is hot. The science teacher asks the students to decide if the mixing of the two chemicals involved a physical or chemical change. He also asks the students to justify their answer. Which student gave the correct response?

• Student 1: The change was physical because a temperature change occurred.

• Student 2. The change was chemical because a temperature change occurred.

• Student 3: The change was physical because the two chemicals mixed.

• Student 4: The change was chemical because the two chemicals mixed.

Tags

NGSS.MS-PS1-2

Which of these elements is most likely to have chemical properties similar to those of calcium (Ca)?

• Magnesium (Mg)

• Neon (Ne)

• Potassium (K)

• Zirconium (Zr)

The simplest form of matter is an element, what is a compound?

• Two elements mixed together in a container.

• Two or more pure substances chemically combined.

• A material found on the Periodic Table.

• Two or more elements physically combined and mechanically separable.

Which of the following represents a compound?

• H

• Cu

• NaCl

• O₃

Tags

NGSS.MS-PS1-1

Which of the following is a Physical Property 

• Toxicity
• Flammability
• Malleability
• Reactivity

Which equation best represents the law of conservation of mass? 

• A
• B
• C
• D

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which statement best explains how periods on the periodic table are organized?

• increasing atomic number from left to right

• increasing number of neutrons from left to right

• decreasing number of electrons from left to right

• decreasing atomic mass number from left to right

An ice cube is put into a heated pan. What will most likely happen to the molecules in the ice as the ice is heated?

• The molecules will begin to move slower.

• The molecules will begin to move faster.

• The molecules will begin to increase in density.

• The molecules will begin to condense in the air.

Tags

NGSS.MS-PS1-4