Energy & Energy Transformations
During photosynthesis, plants use sunlight to make food.
What form of energy from sunlight is transformed into chemical energy?
Solar energy
A substance has a pH of 4.
Is it acidic, neutral, or alkaline?
acidic
A liquid changes into a gas at a specific temperature.
What is this temperature called?
A. Melting point
B. Freezing point
C. Boiling point
D. Room temperature
Boiling point
Elements in the same group on the periodic table generally have:
A. Similar chemical characteristics
B. The same atomic mass
C. The same number of protons
D. The same number of energy levels
Similar chemical characteristics
What is an element?
A. A substance made of only one type of atom
B. A mixture of different substances
C. Two or more compounds mixed together
D. A substance that can always be separated physically
A substance made of only one type of atom
A solar cell is used to power a street lamp.
What is the correct energy transformation?
A. Solar → light
B. Solar → electrical → light and heat
C. Solar → light and heat
D. Heat → light
Solar → electrical → light and heat
Another substance has a pH of 6.
Compared with a substance having a pH of 4, is it more acidic or less acidic?
less acidic
What happens to water when it changes from liquid water into ice?
A. Density increases
B. Density decreases
C. Mass decreases
D. Volume decreases
Density decreases
What do all elements in Group 2 have in common?
A. They are all halogens.
B. They are all alkaline earth metals.
C. They are all nonmetals.
D. They have six valence electrons.
They are all alkaline earth metals.
Which is a characteristic of most metals?
A. Poor conductor of electricity
B. Brittle
C. Good conductor of electricity
D. Dull surface
Good conductor of electricity
In a hydroelectric power station, water stored behind a dam is released and falls.
What is the correct sequence of energy transformations?
A. Kinetic → gravitational → electrical
B. Gravitational → kinetic → electrical
C. Electrical → kinetic → gravitational
D. Chemical → kinetic → electrical
Gravitational → kinetic → electrical
What property of a substance can be determined using a pH indicator?
A. Density
B. Acidity
C. Boiling point
D. Electrical conductivity
Acidity
Which is an example of sublimation?
A. Dew forming on leaves
B. Liquid deodorant evaporating
C. Dry ice changing directly into carbon dioxide gas
D. Ice cream melting
Dry ice changing directly into carbon dioxide gas
Which pair of elements has similar characteristics?
A. Neon and fluorine
B. Chlorine and sulfur
C. Fluorine and chlorine
D. Oxygen and chlorine
Fluorine and chlorine
Which characteristics are generally associated with metals?
A. Shiny, good conductors, malleable
B. Dull, brittle, poor conductors
C. Brittle, poor conductors, dull
D. Poor conductors and malleable
Shiny, good conductors, malleable
A device changes electrical energy into another form of energy that allows it to produce motion.
What type of energy is associated with the movement of an object?
A. Chemical
B. Thermal
C. Kinetic
D. Gravitational
Kinetic energy
A metal has a mass of 13.5 g and a volume of 5 cm³.
What is its density?
A. 2.7 g/cm³
B. 8.5 g/cm³
C. 18.5 g/cm³
D. 67.5 g/cm³
2.7 g/cm³
Formula: Density = Mass ÷ Volume
Which change of state occurs when a gas changes directly into a solid?
A. Sublimation
B. Evaporation
C. Deposition
D. Condensation
Deposition
Why do elements in the same group often have similar chemical properties?
A. They have similar numbers of valence electrons.
B. They have identical atomic masses.
C. They contain the same number of neutrons.
D. They are all the same element.
They have similar numbers of valence electrons.
Which characteristics are generally associated with nonmetals?
A. Shiny and malleable
B. Good conductors of heat and electricity
C. Dull, brittle, and poor conductors
D. Malleable and ductile
Dull, brittle, and poor conductors
A plant uses carbon dioxide, water, chlorophyll, and sunlight during photosynthesis.
What type of energy is stored in the food produced by photosynthesis?
A. Electrical energy
B. Kinetic energy
C. Thermal energy
D. Chemical energy
Chemical energy
A scientist is identifying a metal. It has a melting point above 1,000°C and is one of the best electrical conductors in the table.
The possible metals are aluminum, copper, zinc, silver, and nickel.
Which metal is it?
A. Aluminum
B. Copper
C. Zinc
D. Silver
E. Nickel
Nickel
Identify the changes of state:
An element has characteristics similar to fluorine.
Where would you expect to find another element with similar chemical characteristics?
A. Directly above or below fluorine in its group
B. Directly across the same period
C. In the center of the periodic table
D. In Group 2
Directly above or below fluorine in its group
Bohr's model of the atom describes electrons arranged in energy levels around the nucleus.
What property of an element does the number of valence electrons help determine?
A. Its color
B. Its reactivity
C. Its melting point only
D. Its density only
Its reactivity