2. reflection refraction diffraction polarization
When trying to spear a fish in water, a person needs to take into account the way light bends as it moves from water into air. The bending of light as it passes from one medium into another is known as —
reflection
refraction
diffraction
polarization

3. shape of the guitar body
The pitch of a sound made by plucking a guitar string is determined by the –
strength of the plucking force
distance between the strings
frequency of the vibration produced
shape of the guitar body

4. A pipette is filled with 19. 4 ml of a 35% NaOH solution
A pipette is filled with 19.4 ml of a 35% NaOH solution. The solution is at 22°C and has a density of 1.23 g/mL. According to this information, what is the mass of this NaOH solution?
23.9 g
3.88 g
15.7 g
24.6 g

5. act like metals solidify at room temperature form large molecules
Elements in Group 17 of the periodic table usually-
solidify at room temperature
act like metals
form large molecules
gain an electron when bonding

6. Mg3(PO4)2 MgPO4 Mg2(PO4)3 Mg2PO4
According to the following information, what is the chemical formula for magnesium phosphate? Mg2+ PO43-
Mg3(PO4)2
MgPO4
Mg2(PO4)3
Mg2PO4

7. In this apparatus, the seawater is an example of a -
strong electrolyte
weak acid
nonelectrolyte
strong base

8. a compound an element a mixture an alloy
An unknown silvery powder has a constant melting point and does not chemically or physically separate into other substances. The unknown substance can be classified as-
a compound
an element
a mixture
an alloy

9. Hydrogen (H2) is an example of –
an alloy
a salt
a molecule
a mixture

10. Pain medications can be made as powders or tablets
Pain medications can be made as powders or tablets. The tablets tend to work slower than powder with the same ingredients because a tablet-
dissolves slower in solution than powder
is easier to swallow than powder
has more total mass than powder
travels through the bloodstream more easily

11. Which factor makes water an effective solvent?
The presence of molecular oxygen
Its lack of covalent bonds
Its abundance on Earth’s surface
The polar nature of its molecules

12. Container
Temperature
(°C)
Pressure
(kPa) Q 10
204.5 R 20 S 30
101.3 T 40
The table shows temperature and pressure in four containers holding the same amount of water: According to the table, in which container can the most sodium chloride be dissolved in the water? Q R T S

13. convection refraction radiation conduction
The moon’s surface becomes hot during the long lunar day because the sun transfers heat to the moon. This heat transfer is accomplished almost entirely through the process of —
convection
refraction
radiation
conduction

14. an acid a base a salt an isotope
A certain commercial product used for cleaning ovens must be handled with rubber gloves. The product is slippery and turns litmus paper blue. It probably contains
an acid
a base
a salt
an isotope

15. During an investigation, students accelerated boxes using different forces and then determined the masses of the boxes. What is the mass of a box that requires 0.1 N to make it accelerate 2 m/s2?
0.05 g
50 g
20 g
0.02 g

16. What is the efficiency of a machine if there is a work input of 320 J and a work output of 80J?
25% 4%
400%
240%