Evidence that a chemical reaction has occurred is...
Bubbling, color change, temperature change, new substances formed.
100
The phase of matter in which the particles travel the fastest and the farthest apart.
Gas!
100
How do you find final temperature?
T1 + T2/2 = Tf
100
What is a substance? Give a SPECIFIC example.
Everything. O, H2O, He, NaCl...
100
What is kinetic energy?
The energy of motion.
200
What is a chemical reaction?
When starting substances change into new, different substances.
200
The phase of matter in which an object will melt.
Solid!
200
How do you find heat transferred in calories?
Calories = mass x change in temperature
200
What is a particle? Give a SPECIFIC example?
Everything. O, H2O, He, NaCl...
200
True or false: All objects are always in motion (always have kinetic energy).
True!
300
What happens to atoms when a chemical reaction occurs?
They rearrange. (are not created or destroyed)
300
The phase of matter in which an object will sublime.
Solid!
300
How do you find change in temperature?
Tf - Ti = Change in temperature
300
What is a single element? Give a SPECIFIC example.
One kind of element in a particle or substance. He, O2, Na...
300
Iron and water are the same temperature, which has more energy? Why?
Neither, they are at equilibrium.
400
True or false: A chemical reaction always occurs when substances combine?
False!
400
What happens to the particles in a solid block of lead as it melts?
The kinetic energy of the particles increases until the bonds are broken and they spread apart.
400
How many calories are needed to heat a cup of 200 grams of water from room temperature at 20C to 100C?
16,000 calories
400
What is a compound? Give a SPECIFIC example.
Two or more elements in a particle or substance. H2O, NaCl...
400
Which phase of matter innately has the most energy?
Gas!
500
Write an example of a chemical reaction using chemical formulas.
H2 + O2 = H2O
500
What happens when a volume of air is heated in a closed balloon?
The air particles move faster, the air particles hit each other more frequently, the air particles get farther apart, the air particles occupy more space.
500
Cindy made tea. She started with 300g of water at 20C. She transferred 18,000 calories to the water. What was the final temperature of the water?
80ºC
500
What is the difference between melting and dissolving?
Melting needs one substance while dissolving needs two.