Q: Convert $$139\ \mathrm{cm} to $$meters using scientific notation.

$$1.39 \times 10$$^{-1}$$\ \mathrm{m}$$

Q: Express $$0.000000486 m in $$scientific notation.

$$4.86 \times 10$$^{-7}$$\ \mathrm{m}$$

Q: Which of the following is the correct conversion for $$55.8\ \mathrm{kJ} to $$joules?

$$5.58 \times 10$$^{4}$$\ \mathrm{J}$$

Q: A chemist needs to convert $$6.56 \times 10$$^{-7}$$\ \mathrm{m} to $$nanometers. What is the correct answer?

$$6.56 \times 10$$^{2}$$\ \mathrm{nm}$$

Question 1

Which of the following best describes the difference between a physical and a chemical change?

Accepted Answer

A physical change does not alter the chemical composition, while a chemical change results in the formation of new substances.

Question 2

A student burns 2.00 g of magnesium in a closed container with 5.00 g of oxygen. After the reaction, 6.00 g of magnesium oxide is formed. According to the law of conservation of mass, what mass of oxygen remains unreacted?

Accepted Answer

$$1.00\ \mathrm{g}$$

Question 3

Which of the following is an example of a homogeneous mixture?

Accepted Answer

Salt water

Question 4

Which SI prefix corresponds to $$10^{-6}$$?

Accepted Answer

Micro-

Question 5

Convert $$139\ \mathrm{cm} to $$meters using scientific notation.

Accepted Answer

$$1.39 	imes 10$$^{-1}$$\ \mathrm{m}$$

Question 6

Which of the following is a derived SI unit?

Accepted Answer

Cubic meter

Question 7

A measurement is recorded as $$0.004560 g. $$How many significant figures does this value have?

Accepted Answer

5

Question 8

Which of the following is an example of an exact number?

Accepted Answer

The number of students in a classroom

Question 9

Which of the following best describes the arrangement of particles in a solid, as shown in the first image?

Accepted Answer

Particles are closely packed in a fixed, orderly arrangement.

Question 10

A sample of matter is uniform throughout and can be separated into simpler substances only by chemical means. How should this sample be classified?

Accepted Answer

Compound

Question 11

Express $$0.000000486 m in $$scientific notation.

Accepted Answer

$$4.86 	imes 10$$^{-7}$$\ \mathrm{m}$$

Question 12

Which of the following is a physical property?

Accepted Answer

Boiling point

Question 13

A student multiplies $$3.24 (3 $$sig figs) by $$2.1 (2 $$sig figs). What is the correct number of significant figures in the final answer?

Accepted Answer

2

Question 14

Which of the following is the correct conversion for $$55.8\ \mathrm{kJ} to $$joules?

Accepted Answer

$$5.58 	imes 10$$^{4}$$\ \mathrm{J}$$

Question 15

Which of the following best describes the difference between mass and weight?

Accepted Answer

Mass is the amount of matter in an object, while weight is the force of gravity acting on that mass.

Question 16

A chemist needs to convert $$6.56 	imes 10$$^{-7}$$\ \mathrm{m} to $$nanometers. What is the correct answer?

Accepted Answer

$$6.56 	imes 10$$^{2}$$\ \mathrm{nm}$$

Question 17

Which of the following is NOT a base SI unit?

Accepted Answer

Liter

Question 18

Which of the following best describes a heterogeneous mixture?

Accepted Answer

A mixture with visibly different parts or phases

Question 19

Which of the following is the correct order of steps in the scientific method as applied in chemistry?

Accepted Answer

Observe, hypothesize, experiment, modify or conclude

Question 20

A chemist converts $$2235\ \mathrm{ft/s} to$$ $$\mathrm{km/hr}. $$Which technique is most appropriate for this conversion?

Accepted Answer

Dimensional analysis (factor-label method)

Essential Chemistry Tools and Ideas: Foundations of General Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard