A self-warming packet can be used to warm hands during cold weather. Powdered iron (Fe) reacts with oxygen (O2) when the packet is exposed to air. With the addition of a salt catalyst, Fe2O3 (iron oxide) is quickly formed and heat is given off.
Which term best describes iron oxide?

• compound
• mixture
• element
• ion

Tags

NGSS.MS-PS1-1

What do any two samples of the element mercury (Hg) have in common?

• same mass
• same volume
• same type of atom
• same number of electrons

A student mixes salt and water in a beaker to form a solution. What properties of the substances would allow the student to then separate the components?

• desnities
• particle size
• boiling point
• electrical conductivity

Tags

NGSS.MS-PS1-2

In the reaction, iron reacts with water to form iron oxide and hydrogen gas
Which of these best describes the iron (Fe) reactant?

• element
• compound
• ion 
• mixture

A student observes a substance that is highly reflective and able to conduct electricity. The substance also has a high melting point. Which is the most likely classification for this substance?

• salt
• glass
• metal
• plastic

Tags

NGSS.HS-PS1-3

Which can be broken down chemically into simpler substances?

• atom
• isotope
• compound
• element

Tags

NGSS.MS-PS1-5

When water evaporates from Earth’s surface into the atmosphere, its molecules enter the gas state. What change in this gas causes molecules to condense into the small water droplets that form clouds?

• mass is reduced
• volume is increased
• temperature is reduced
• pressure is increased

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A sample in a cylindrical container has a cylindrical shape and a fixed volume. The state of matter of the sample

• must be solid.
• could be either solid or liquid.
• must be liquid
• could be either liquid or gas

Energy is absorbed and released through endothermic and exothermic processes. Which is an example of an exothermic process? ( Hint: Heat exits )

• ice melting
• ice sublimating
• water evaporating
• water freezing

Tags

NGSS.MS-PS3-4

Water puddles on a sidewalk evaporate when the Sun heats the water. Which of these best describes what is happening as the water evaporates?

• Water changes phase as it releases heat to the environment.
• Water boils as it absorbs energy from the sidewalk
• Water becomes a gas as it absorbs energy from the Sun.
• Water evaporates as its thermal energy is transferred to the air

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5