Science

Which of the following could be used to convert light energy to electrical energy?

solar cell

Which group in the periodic table forms ions that have a valence of 1+?

A) 1 (periodic table question)

A sound wave is produced and begins to travel from left to right through four different media. The speed of the wave varies as it travels. The media are solid, liquid, gas, and a vacuum, but not necessarily that order. 1- 344 m/sec 2-5000 m/sec 3- 1450 m/sec 4- no transmission

A) 1 (sound wave question)

What force must be applied to the rope in the pulley shown in the diagram above to lift the 10-N block.

A) 5N

A force (F1) is required to pull a 20-kg box across a carpeted floor. What is typically true about the force (F2) required to pull the box across the ice at a rink?

A) F1 is greater than F2

Which of the following structures represents a saturated hydrocarbon?

A) The one with the H's and the C's in an extended H form

Which of the following pairs are isotopes of the same element

A) atom J (27 protons and 32 neutrons) and atom L (27 protons, 33 neutrons)

Albert stirs a mug of hot chocolate with a metal spoon. What type of heat transfer is responsible for the spoon getting hot?

A) conduction

four people are pulling on the box with the forces shown below. If there are no other forces on the box in what direction will it move?

A) directly toward Diane

The number of protons in a neutral atom is equal to the number of

A) electrons

Parallel rays of light pass through the lens shown above. Which of the following diagrams BEST shows the path of the rays emerging from the right side of the lens?

A) looks like a teepee

in normal air, which of the following substances is MOST common?

A) nitrogen

The melting of wax is a physical change, yet the burning of wax is a chemical change. What is the essential difference between the physical change and the chemical change of wax in a burning candle?

A) the burning of wax forms new compounds, while the melting of wax does not.

To operate an electric train set, a transformer must reduce 120 volt house current to 6 volts. What is the ratio between turns on the primary (120 volt) side and the secondary (6 volt) side?

B) 20:1

examine the drawing of a water molecule. (looks like mickey mouse on its side)

B) 3 atoms and 10 electrons

Which of the following situations violates the law of conservation of energy?

B) A block sliding freely on level ice increases in speed until it hits a wall

Which of the following contains the MOST atoms?

B) Al2(SO4)3

An ionic bond typically forms between certain types of elements. Which pair of elements will form an ionic compound?

B) K and Cl

What is the correct formula for the compound formed when lithium and oxygen combine?

B) Li2O

Carbon atoms can link themselves together into long chains and rings to form a vast number of highly complicated molecules. Which of the following statements BEST explains why carbon atoms behave this way?

B) They easily form covalent bonds with each other

Which of the following is MOST likely to contain information on a new scientific discovery?

B) a current scientific magazine

The stored energy in a battery can BEST be described as:

B) chemical

Which process is represented by the following description: "sugar is added to water and a sweet liquid after stirring"?

B) dissolving

In a restaurant kitchen, lamps are used to keep food warm. Which type of electromagnetic radiation does the lamps emit that is responsible for keeping the food warm?

B) infrared

aluminum oxide (Al2O3) is produced by combining Al3+ and O2- particles. What type of compound has been formed?

B) ionic

As you move from left to right across a row of elements in the periodic table, what happens to the number of neutrons in a typical atom?

B) it increases

Shaina uses a shovel to dig a hole to plant a tree. A shovel is an example of a compound machine because it is made up of what two simple machines?

B) lever and wedge

By which process does a lens focus light

B) refraction

The figure below shows how the word "ambulance" is painted on the front of some vehicles so that it reads correctly in the rearview mirror that is attached to the windshield of a car driving in front of the ambulance.

B) reverses the left and the right sides of objects

On Monday, the janitor places an air freshener in the gym. It is a shiny, pink disk. Over the next several days, the disk gradually begins to shrink. Which of the following statements is a valid interference?

B) the disk is undergoing a physical change

Pat measures a small rubber ball and then makes three other balls of the same diameter from lead, foam, and wood. Which ball has the greatest inertia? A. the rubber ball B. the lead ball C. the foam ball D. the wood ball

B) the lead ball

A student connects three identical light bulbs in a parallel to a dry cell as shown below. what happens when the student removes one of the light bulbs from its socket?

B)The other light bulbs remain on and will be equally bright

four pairs of objects have the masses shown below. if the objects in each pair are the same distance apart the gravitational force between the objects in which pair is the greatest?

D) 2 kilograms and 2 kilograms

A block of aluminum will be used to determine the density of aluminum. If the aluminum block measures 2cm by 3 cm by 6 cm what is its volume?

D) 36cm

Four identical light bulbs are connected in a circuit as shown below The current is greatest through which of the light bulbs?

D) 4

A helicopter is moving past some clouds at a speed of 5 km / hr north relative to the clouds. The clouds are moving past the ground at a velocity of 3.5 km / hr north. How fast is the helicopter going past the ground?

D) 8.5 km/hr

Mike wants to determine the weights of some small stones. He places each of them on a scale that measures the mass of each stone. mike's final results should be reported in which metric unit?

D) Newtons

Tomal performed a flame test by burning a small amount of an unknown substance in the flame of a Bunsen Burner. The flame turned BLUE. It is MOST likely that the unknown substance.

D) copper

In order to determine the speed of an object, what measurements must be made?

D) distance and time

Which procedure is unsafe when heating a liquid in a test tube

D) looking down the test tube to check for boiling

Which one of these energy source is a nonrenewable source?

D) natural gas

Janelle is starting a research project on transistors. She goes to the Web site that has links organized by topic. In which of the following topics should Janelle begin her search?

D) physics

The height, weight, and width of the block shown below are all different. using this block, a student wants to test a hypothesis that frictional forces are independent of the area of contact between the block and the surface it slides on. Which method is BEST to collect the data needed?

D) pulling the box across three different surfaces

Which of the following laboratory practices is frequency followed but not necessary for safety?

D) rinse all glassware with distilled water before use

Which of the following is the best representation of molecules of water vapor?

D) the mickey mouse ones

In the absence of air resistance, which of these objects will fall at the fastest rate when dropped mass of 25 kg medium mass of 10kg biggest mass of 75kg smallest

D) they fall at the same rate

Radioactive isotopes are commonly used as

D) tracers in biochemical reactions

A box of weight W is lifted by a force F using a lever as shown below What is the mechanical advantage of the lever?

C) 3

What number should precede H2 in the chemical equation below in order for the equation to be balanced?

C) 3

An inclined plane is used to move a heavy box from the ground into the bed of the truck If 100 N of force is required to move the load up the ramp, how much work is done? Disregard any force of friction. height= 1m inclined plane= 4m

C) 400 J

Which equation below is correctly balanced?

C) AsCl3+ 3H2O->3HCl+ As(OH)3

Which of the following is an example of a situation in which exothermic chemical reactions occur?

C) Fireworks explode during a holdiay

Which pair of elements is MOST similar

C) Ne and Ar

A lab group of five students each used the same meter stick to measure the length of an aluminum rod. They made their measurements over a 5 minute time interval. Their results are shown in the table below. 1- 36.5 2-37.5 3-37.5 4-37.5 5-38.5 On the basis of these results only, which of these conclusions is MOST valid?

C) The reported length of the rod is 37.5 because that is the average of the measurements

Dale and Wallace are investigating static friction using a block and ramp. Their procedure is to raise the ramp in five-degree increments while adding five-gram mass to the block. Which statement exactly describes this experimental procedure?

C) This is poor experimental procedure because they are changing too many variables

A piece of blue paper appears blue because the paper...

C) absorbs all colors of light except for blue

The compound formed from the elements calcium and chlorine is known as

C) calcium chlorine

Which of the following are transferred or shared when two atoms react chemically?

C) electrons

In level flight at constant speed, which pair of forces must be equal?

C) lift and weight

The International System of Units (SI) is a standardized system of measurement. Which of the following metrics are used to measure the mass quantities of time, mass, and time, respectively, in the SI system?

C) meter, kilogram, second

A car was sitting in sunlight all day long. The heat that is now contained in the car was transferred to the car primarily by which of the following processes?

C) radiation

Which of the following is a chemical property of iodine

C) reacts with starch to gives a dark blue color

2Al(s)+3CuCl2(aq)->2AlCl3(aq)+ 3Cu(s) This is an example of what type of reaction?

C) single displacement

In an atom, which force holds the protons and neutrons together in the nucleus?

C) strong force

A large number of iron nails were kept in containers in a humid room. Some of the containers were open, and some were airtight. Sixty percent of the nails kept in open containers developed rust. Which of the following would be important to the conclusion about whether the humidity might have contributed to the rusting?

C) the percentage of nails in airtight containers that also developed rust

an aluminum bar was found to have a mass of 27g. Using water displacement, the volume was measured to be 10mL. What is the density of the aluminum?

C)2.7 g/mL

why did Dimitri Mendeleev use atomic masses instead of atomic numbers to organize his first periodic table in 1869?

scientists did not know about atomic numbers in 1869

In the periodic table, the rows are called

a) periods

pauline needs to measure the sliding friction of a brick. how should she go about doing this?

drag the brick by a string attached to a spring scale along the surface of a table at a constant speed and read the force

the weight of a person on Earth is 6 times his or her weight on the moon. what type of force is responsible for a person's weight?

gravitational

mr. jacobs gives four groups of students an ice cube that they are to keep from melting as best as they can. an ice cube melts the LEAST over a period of one hour when it is...

in a glass jar and the jar is completely covered in aluminum foil

Soft drinks consist of a mixture of water, sugar, and flavoring, with carbon dioxide gas bubbled through it. Which of these ingredients would be considered the solvent?

water