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

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

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

Elements in Group 17 of the periodic table usually-

act like metals solidify at room

temperature

form large molecules

gain an electron when bonding

According to the following information, what is the chemical

formula for magnesium phosphate? Mg2+ PO43-

MgPO4Mg3(PO4)2

Mg2(PO4)3 Mg2PO4

In this apparatus, the seawater is an example of a -

weak acid strong electrolyte

nonelectrolyte strong base

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-

an element

a mixture an alloy

a compound

Hydrogen (H2) is an example of –

an alloy a salt

a molecule a mixture

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

Which factor makes water an effective solvent?

The presence of molecular oxygen

Its lack of covalent bonds

The polar nature of its molecules

Its abundance on Earth’s surface

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

Container Temperature(°C)

Pressure(kPa)

Q 10 204.5

R 20 204.5

S 30 101.3

T 40 101.3

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

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

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

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%