Matter
Which two properties must something have to be considered matter?
Mass and volume.
Dry ice changing directly to gas is called what?
Sublimation
Which is more acidic: vinegar (pH 3) or soda (pH 5)?
Vinegar.
What is the formula for density?
Density = Mass / Volume.
Which is an Element: air, salt, or gold?
Gold.
Is light considered matter? Why or why not?
No, it has no mass or volume
What property allows metals to be drawn into wires?
Ductility
A solution with pH 12 is strong or weak base?
Strong base
An object has a mass of 100 g and a volume of 25 mL. What is its density?
4 g/mL.
Which is a mixture: salt water or table salt?
Salt Water.
Why is air considered matter even though it is invisible?
It has mass and takes up space.
Why is rusting a chemical change and What is the indicator?
A new substance (iron oxide) forms with change in color
What does the pH scale actually measure?
The concentration of H⁺ ions.
Why does sugar dissolve faster in hot water than cold water?
Higher temperature increases particle motion and thus increases the solubility.
Which type of mixture has unevenly distributed particles, like a salad?
Heterogeneous.
What tool can you use to measure the mass of matter?
Balance or Scale
Which ion is produced by acids in water?
H⁺ ions.
Why does water heat up more slowly than sand?
Water has a higher specific heat.
If no more solute can dissolve, the solution is called what?
Saturated solution.
Photosynthesis is what type of reaction: exothermic or endothermic?
Endothermic (absorbs sunlight / Energy).
What happens to particle motion when temperature increases and Why?
Particle motion increases because there has been an addition of energy.
Which ion is produced by bases in water? Does pH measure this ion?
OH⁻ ions. It measures H+ ions.
Which heats faster, oil or water? Why?
Oil, because it has lower specific heat.
Why does stirring help a solute dissolve faster?
An external energy is given which helps the particles evenly through the solvent.
Which separation method would you use to separate sand from water?
Filtration, because the solid particles are trapped by the filter while water passes through.