Question 1

Which of the following statements best describes the difference between a scientific law and a scientific theory?

Accepted Answer

A scientific law describes a consistent relationship observed in nature, often expressed mathematically, while a scientific theory explains the underlying reasons for those relationships.

Question 2

A sample of a metal has a mass of $$ 45.0 \ \mathrm{g} $$ and a volume of $$ 15.0 \ \mathrm{cm}^3 . $$What is the density of the metal?

Accepted Answer

$$ 3.00 \ \mathrm{g/cm}^3 $$

Question 3

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

Accepted Answer

A salad with lettuce, tomatoes, and cucumbers

Question 4

Convert $$ 0.00056  to $$scientific notation.

Accepted Answer

$$ 5.6 	imes 10$$^{-4}$$ $$

Question 5

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

Accepted Answer

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

Question 6

A student measures the mass of a sample three times and gets values of $$ 2.51 \ \mathrm{g} $$, $$ 2.50 \ \mathrm{g} $$, and $$ 2.52 \ \mathrm{g} . $$The true mass is $$ 2.00 \ \mathrm{g} . $$Which statement best describes the measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 7

Which of the following correctly lists the three main subatomic particles, their charges, and their relative locations in the atom?

Accepted Answer

Proton: positive, nucleus; Neutron: neutral, nucleus; Electron: negative, outside nucleus

Question 8

A compound contains $$ 2 $$ atoms of zinc, $$ 3 $$ atoms of phosphorus, and $$ 8 $$ atoms of oxygen. What is its chemical formula?

Accepted Answer

$$ \mathrm{Zn}_2(\mathrm{PO}_4)_3 $$

Question 9

Which of the following is the correct formula for calculating the amount of heat absorbed or released by a substance?

Accepted Answer

$$ q = mC\Delta T $$

Question 10

A sample of water is heated from $$ 25.0 \, ^\circ \mathrm{C}  to$$ $$ 75.0 \, ^\circ \mathrm{C} . $$What is the temperature change $$ (\Delta T)  in $$Kelvin?

Accepted Answer

$$ 50.0 \ \mathrm{K} $$

Question 11

Which of the following best describes the organization of the periodic table?

Accepted Answer

Elements are arranged by increasing atomic number, with similar chemical properties grouped in columns.

Question 12

Which of the following is a correct example of a polyatomic ion?

Accepted Answer

$$ \mathrm{SO}_4$$^{2-}$$ $$

Question 13

A student needs to convert $$ 5.00 \ \mathrm{km}  to$$ $$ \mathrm{cm} . $$Which of the following is the correct answer?

Accepted Answer

$$ 500,000 \ \mathrm{cm} $$

Question 14

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 15

Which of the following is the correct name for $$ \mathrm{FeCl}_3 $$?

Accepted Answer

Iron(III) chloride

Question 16

A sample contains $$ 70.0\% $$ isotope A (mass $$ 10.0 \ \mathrm{amu} ) $$and $$ 30.0\% $$ isotope B (mass $$ 11.0 \ \mathrm{amu} ). $$What is the average atomic mass?

Accepted Answer

$$ 10.3 \ \mathrm{amu} $$

Question 17

Which of the following is a correct example of a binary molecular compound?

Accepted Answer

$$ \mathrm{CO}_2 $$

Question 18

Which of the following is the correct conversion from $$ 25.0 \, ^\circ \mathrm{C}  to $$Kelvin?

Accepted Answer

$$ 298.15 \ \mathrm{K} $$

Question 19

Which of the following best describes the difference between potential and kinetic energy?

Accepted Answer

Potential energy is stored energy due to position or composition, while kinetic energy is the energy of motion.

Question 20

Which of the following is the correct number of significant figures in the measurement $$ 0.00450 $$?

Accepted Answer

3

CHE 1011 Exam 1 Review: Foundations of Chemistry

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