Q: Which of the following is a correct conversion factor for converting inches to centimeters?

$$1 \ \text{in} = 2.54 \ \text{cm}$$

Q: Which of the following is the correct balanced equation for the beta decay of $$^{14}\text{C}$$?

$$^{14}\text{C} \$$rightarrow ^{14}$$\text{N} + \beta^-$$

Question 1

Which of the following best describes a homogeneous mixture?

Accepted Answer

A mixture in which the composition is uniform throughout, such as salt dissolved in water.

Question 2

Which of the following is the correct symbol and atomic number for the element with 57 protons?

Accepted Answer

La, 57

Question 3

Which of the following is a correct conversion factor for converting inches to centimeters?

Accepted Answer

$$1 \ 	ext{in} = 2.54 \ 	ext{cm}$$

Question 4

A sample of a metal has a mass of $$25.0 \ 	ext{g}$$ and a volume of $$2.00 \ 	ext{cm}^3. $$What is its density?

Accepted Answer

$$12.5 \ 	ext{g/cm}^3$$

Question 5

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 6

Which of the following best describes the process of beta decay?

Accepted Answer

A neutron in the nucleus is converted into a proton and an electron, and the electron is emitted.

Question 7

Which of the following ions is polyatomic?

Accepted Answer

$$	ext{SO}_4$$^{2-}$$

Question 8

A patient receives a radioactive tracer with a half-life of 6 hours. If the initial activity is $$80 \ 	ext{mCi}$$, what will the activity be after 18 hours?

Accepted Answer

$$10 \ 	ext{mCi}$$

Question 9

Which of the following best explains why water has a high specific heat capacity?

Accepted Answer

Hydrogen bonding between water molecules requires more energy to increase temperature.

Question 10

Which of the following is the correct balanced equation for the beta decay of $$^{14}	ext{C}$$?

Accepted Answer

$$^{14}	ext{C} \$$rightarrow ^{14}$$	ext{N} + \beta^-$$

Question 11

Which of the following best describes the octet rule?

Accepted Answer

Atoms tend to gain, lose, or share electrons to achieve eight electrons in their valence shell.

Question 12

Which of the following is the correct electron configuration for a neutral atom of magnesium ($$Z=12$$)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$

Question 13

Which of the following is a correct statement about the difference between a compound and a mixture?

Accepted Answer

A compound has a fixed composition and can only be separated by chemical means, while a mixture can be separated by physical means.

Question 14

Which of the following is the correct formula for calculating specific heat ($$c$$)?

Accepted Answer

$$c = \dfrac{q}{m \Delta T}$$

Question 15

Which of the following ions is isoelectronic with neon ($$	ext{Ne}$$)?

Accepted Answer

$$	ext{Na}^+$$

Question 16

A radioactive isotope has a half-life of 3 days. How much of a 32 g sample remains after 9 days?

Accepted Answer

$$4 \ 	ext{g}$$

Question 17

Which of the following best describes the difference between alpha and gamma radiation?

Accepted Answer

Alpha radiation consists of particles with mass and charge, while gamma radiation is massless and uncharged.

Question 18

Which of the following is the correct name for the ion $$	ext{NH}_4^+$$?

Accepted Answer

Ammonium

Question 19

Which of the following best explains why noble gases are generally unreactive?

Accepted Answer

They have a complete octet in their valence shell.

Question 20

Which of the following is the correct balanced equation for the reaction of sodium with water?

Accepted Answer

$$2	ext{Na} + 2	ext{H}_2	ext{O} ightarrow 2	ext{NaOH} + 	ext{H}_2$$

CHEM 1150 Exam 1 Study Guide: GOB Chemistry Fundamentals

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