CHEM: Heat & Energy (with calculations)

Which of the following is an example of a number written in scientific notation?

• 3.45

• 3.45 x 10₄

• 345 x 10²

• 3.45 x 10²

Convert 420 Joules into calories

(a)  

Convert that number into Calories

​ (b)   ​

• 100.38
• 10.038
• 0.10038
• 100,380
• 10,380
• 1,000.38
• 0.010380

How many calories are in a dinner containing 3.5 x 10² joules?

(a)  

How many Calories are in that same dinner?

​ (b)  

• 83.65
• 0.084
• 1464
• 0.84
• 840
• 8,400
• 84,000

When a  piece of aluminum foil is taken out of the oven and cools from 125° C to 53°C, What is the change in temperature?

• 72°C

• 178°C

• 125°C

• 53°C

How would you write 36,820,000 in Scientific Notation?

a

b

7

368.2

36.82

3

0.3682

-7

3.682

3.6

-3

How would you write 0.0023 in Scientific Notation?

a

h

0.23

23

2.0

-3

3

2.3

-2.3

-23

Match the number in standard notation to it's match in scientific notation:

• 3,500

• 3.5 x 10^-3

• 0.0035

• 3.5 x 10³

• 0.00000035

• 3.5 x 10⁷

• 35,000,000

• 3.5 x 10⁰

• 3.5

• 3.5 x 10^-7

Select all that are TRUE: A runner eats a meal with a nutritional energy of 548 Calories. After her meal, she burns 2.0 ✕ 10⁶ joules while running.

• there were 548,000 calories of energy in the meal

• there were 2.29 x 10⁶ joules of energy in the meal

• the runner burned 478 Calories during her run

• the runner ate less Calories than she burned

• the runner burned 4.78 x 10⁵ calories

Match the type of energy to the correct example:

• sound energy

• runner

• thermal energy

• coal

• kinetic energy

• charged particles

• chemical potential energy

• radio

• electrical energy

• fuel burning

A(n) ​ (a)   system is one where matter and energy can both be transferred in and out. A(n) ​ (b)   system is one where only energy can be transferred in and out.

• open
• closed
• isolated
• semi-open