CHEMISTRY

Question 1

What is the smallest unit of an element?

Answer 1

An atom.

Question 2

True or False: Ions are atoms that have gained or lost electrons.

Answer 2

True.

Question 3

What is the charge of a cation?

Answer 3

Positive.

Question 4

What is the charge of an anion?

Answer 4

Negative.

Question 5

Fill in the blank: The basic unit of a chemical compound is called a ______.

Answer 5

Molecule.

Question 6

Which subatomic particle has a negative charge?

Answer 6

Electron.

Question 7

What is the central part of an atom called?

Answer 7

Nucleus.

Question 8

What are the three primary subatomic particles?

Answer 8

Protons, neutrons, and electrons.

Question 9

What is the periodic table used for?

Answer 9

To organize elements by their atomic number and properties.

Question 10

Which element has the atomic number 1?

Answer 10

Hydrogen.

Question 11

True or False: Compounds are mixtures of two or more substances that retain their individual properties.

Answer 11

False.

Question 12

What is a mixture?

Answer 12

A combination of two or more substances that do not chemically bond.

Question 13

What is the ionic formula for sodium chloride?

Answer 13

NaCl.

Question 14

Fill in the blank: The number of protons in an atom determines its ______.

Answer 14

Atomic number.

Question 15

What is the mass number of an atom?

Answer 15

The sum of protons and neutrons in the nucleus.

Question 16

Which group of the periodic table contains noble gases?

Answer 16

Group 18.

Question 17

What is the difference between an element and a compound?

Answer 17

An element is a pure substance made of one type of atom, while a compound is made of two or more different atoms chemically bonded.

Question 18

True or False: Isotopes are atoms of the same element with different numbers of neutrons.

Answer 18

True.

Question 19

What defines a solution?

Answer 19

A homogeneous mixture where one substance is dissolved in another.

Question 20

What is a polyatomic ion?

Answer 20

An ion composed of two or more atoms.

Question 21

Which element is represented by the symbol ‘O’?

Answer 21

Oxygen.

Question 22

What type of bond forms between two ions?

Answer 22

Ionic bond.

Question 23

Fill in the blank: The elements in the same column of the periodic table share similar ______.

Answer 23

Properties.

Question 24

What is the formula for calculating the number of neutrons in an atom?

Answer 24

Mass number - Atomic number.

Question 25

True or False: All mixtures are homogeneous.

Answer 25

False.

Question 26

What does the term 'atomic mass' refer to?

Answer 26

The weighted average mass of an element's isotopes.

Question 27

Symbol for sodium

Answer 27

Na

Question 28

What is the pH range of acids?

Answer 28

0 to 7

Question 29

What is the pH range of bases?

Answer 29

7 to 14

Question 30

True or False: A pH of 7 is considered neutral.

Answer 30

True

Question 31

Fill in the blank: Acids release _____ ions in solution.

Answer 31

hydrogen

Question 32

Fill in the blank: Bases release _____ ions in solution.

Answer 32

hydroxide

Question 33

What is the formula for calculating pH?

Answer 33

pH = -log[H+]

Question 34

What are the three general acid-base reactions?

Answer 34

Neutralization, acid-carbonate, and acid-metal reactions

Question 35

What happens during a neutralization reaction?

Answer 35

An acid reacts with a base to produce water and a salt.

Question 36

True or False: All acids are corrosive.

Answer 36

False

Question 37

What gas is produced when an acid reacts with a carbonate?

Answer 37

Carbon dioxide (CO2)

Question 38

What is a common indicator used to test pH?

Answer 38

Litmus paper

Question 39

What color does litmus paper turn in acidic solutions?

Answer 39

Red

Question 40

What color does litmus paper turn in basic solutions?

Answer 40

Blue

Question 41

True or False: Acetic acid is a strong acid.

Answer 41

False

Question 42

What is a strong acid?

Answer 42

An acid that completely dissociates in water.

Question 43

Give an example of a strong base.

Answer 43

Sodium hydroxide (NaOH)

Question 44

What is physical change?

Answer 44

A change that does not alter the chemical composition of a substance.

Question 45

What is a chemical change?

Answer 45

A change that results in the formation of new chemical substances. Cannot be reversed.

Question 46

What gas is typically tested for using a glowing splint?

Answer 46

Oxygen

Question 47

What gas is tested for using a lighted splint?

Answer 47

Oxygen

Question 48

What is the result of a hydrogen gas test?

Answer 48

A 'pop' sound

Question 49

What is the expected result when carbon dioxide is bubbled through limewater?

Answer 49

It turns milky.

Question 50

What does a pH of 14 indicate?

Answer 50

A strong base

Question 51

What is the effect of dilution on the pH of an acid?

Answer 51

It increases the pH (makes it less acidic).

Question 52

True or False: Strong acids have a higher pH than weak acids.

Answer 52

False

Question 53

What is the relationship between pH and hydrogen ion concentration?

Answer 53

As pH decreases, hydrogen ion concentration increases.

Question 54

What is the main component in vinegar?

Answer 54

Acetic acid

Question 55

What is the formula for determining the total number of atoms in an ionic compound?

Answer 55

The total number of atoms is the sum of the atoms from each ion in the formula.

Question 56

True or False: The formula NaCl contains one sodium atom and one chlorine atom.

Answer 56

True

Question 57

Fill in the blank: In the ionic formula CaCl2, there are _____ chlorine atoms.

Answer 57

2

Question 58

How many atoms are in the ionic formula Mg3(PO4)2?

Answer 58

11 atoms (3 magnesium, 2 phosphorus, and 8 oxygen)

Question 59

Which of the following formulas contains the greatest number of atoms? a) Na2SO4 b) K2Cr2O7 c) Al(NO3)3

Answer 59

c) Al(NO3)3 (contains 12 atoms)