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Matter, States, and Energy Changes
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Matter, States, and Energy Changes
Matter, States, and Energy Changes
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1
Question
How do reactants and products differ in a chemical reaction?
Page 1
Answer
Reactants are converted into products. Memory hook: reactants enter the reaction station; products leave it.
2
Question
Which energy change characterizes an exothermic reaction?
Page 1
Answer
It releases energy. The thermite reaction and combustion are examples.
3
Question
Which energy change characterizes an endothermic reaction?
Page 1
Answer
It gains energy. An instant cold pack is an example.
4
Question
How does water’s phase sequence distinguish endothermic change?
Page 1
Answer
Solid → liquid → gas is endothermic. Memory hook: follow water uphill through the phases.
5
Question
How does the reverse water phase sequence relate to energy?
Page 1
Answer
Gas → liquid → solid is exothermic. Memory hook: water travels downhill through the phases.
6
Question
What is the memory hook for water’s endothermic phase sequence?
Page 1
Answer
“Uphill through the phases”: solid → liquid → gas is endothermic.
7
Question
Which temperature conversion formula gives kelvins from Celsius?
Page 1
Answer
K = °C + 273.15
8
Question
Which formula converts Celsius temperature to Fahrenheit?
Page 1
Answer
°F = (1.8)°C + 32, or °F = (9/5)°C + 32
9
Question
Which state of matter has definite shape and definite volume?
Page 1
Answer
A solid has definite shape and definite volume.
10
Question
Which state has indefinite shape but definite volume?
Page 1
Answer
A liquid has indefinite shape and definite volume.
11
Question
Which state has both indefinite shape and indefinite volume?
Page 1
Answer
A gas has indefinite shape and indefinite volume.
12
Question
What is the contrast hook for shape and volume across the three states?
Page 1
Answer
Solid: both definite. Liquid: shape indefinite, volume definite. Gas: both indefinite. Hook: “both, half, neither.”
13
Question
Which description defines a substance in these notes?
Page 1
Answer
A kind of matter with uniform and definite composition.
14
Question
Which examples are listed as physical properties of matter?
Page 1
Answer
Color, odor, mass, density, and hardness.
15
Question
How does a physical change affect a substance’s composition?
Page 1
Answer
It alters the substance without altering its composition.
16
Question
What is wrong with thinking every change alters composition?
Page 1
Answer
A physical change alters a substance without changing its composition.
17
Question
Complete the Celsius-to-kelvin conversion: K = °C + _____.
Page 1
Answer
273.15
18
Question
Complete the definition: A physical change alters a substance without altering its _____.
Page 1
Answer
composition