CHEMISTRY 2

Question 1

What is the atomic number of carbon?

Answer 1

6

Question 2

True or False: The pH scale measures acidity and basicity.

Answer 2

True

Question 3

Fill in the blank: The chemical formula for water is ___

Answer 3

H2O

Question 4

What is the primary gas produced during photosynthesis?

Answer 4

Oxygen

Question 5

Which of the following is a noble gas? A) Oxygen B) Argon C) Nitrogen

Answer 5

B) Argon

Question 6

What is the difference between an element and a compound?

Answer 6

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

Question 7

What is the law of conservation of mass?

Answer 7

Mass is neither created nor destroyed in a chemical reaction.

Question 8

True or False: Acids turn blue litmus paper red.

Answer 8

True

Question 9

What is the chemical symbol for sodium?

Answer 9

Na

Question 10

Atomic number for Neon?

Answer 10

10

Question 11

Fill in the blank: The process of a solid turning directly into a gas is called ___.

Answer 11

sublimation

Question 12

Which part of the atom has a positive charge?

Answer 12

Proton

Question 13

What is the main difference between ionic and covalent bonds?

Answer 13

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Question 14

Which of the following is an example of a physical change? A) Burning wood B) Melting ice C) Rusting iron

Answer 14

B) Melting ice

Question 15

What is the formula for calculating the number of moles?

Answer 15

Moles = Mass (g) / Molar Mass (g/mol)

Question 16

True or False: All substances are made of matter.

Answer 16

True

Question 17

What is the periodic table used for?

Answer 17

To organize elements based on their atomic number, electron configuration, and recurring chemical properties.

Question 18

What is an isotope?

Answer 18

Atoms of the same element with different numbers of neutrons.

Question 19

Fill in the blank: The pH of pure water is ___.

Answer 19

7

Question 20

True or False: A physical change can be reversed.

Answer 20

True

Question 21

Which gas is commonly associated with respiration?

Answer 21

Carbon dioxide

Question 22

What is the main purpose of a chemical equation?

Answer 22

To represent a chemical reaction in terms of reactants and products.

Question 23

True or False: Electrons have a negative charge.

Answer 23

True

Question 24

What is a solution?

Answer 24

A homogeneous mixture of two or more substances.

Question 25

What does 'solubility' refer to?

Answer 25

The ability of a substance to dissolve in a solvent.

Question 26

What is the molar mass of water (H2O)?

Answer 26

18 g/mol

Question 27

Fill in the blank: The smallest unit of an element is called an ___.

Answer 27

atom

Question 28

What is an acid-base reaction?

Answer 28

A chemical reaction where an acid reacts with a base to produce water and a salt.

Question 29

What is the primary component of air?

Answer 29

Nitrogen

Question 30

Which of the following has the highest electronegativity? A) Fluorine B) Oxygen C) Nitrogen

Answer 30

A) Fluorine

Question 31

True or False: Chemical changes can be reversed easily.

Answer 31

False

Question 32

What is the definition of 'reactants'?

Answer 32

Substances that undergo a chemical change in a reaction.

Question 33

What is a polymer?

Answer 33

A large molecule made up of repeating structural units called monomers.

Question 34

Fill in the blank: The process of a gas turning into a liquid is called ___.

Answer 34

condensation

Question 35

Which element is essential for the formation of DNA?

Answer 35

Phosphorus

Question 36

What is the atomic number of Silicon?

Answer 36

14

Question 37

What is the atomic number of Carbon?

Answer 37

6

Question 38

Which element has the chemical symbol 'Na'?

Answer 38

Sodium

Question 39

True or False: Helium is a metal.

Answer 39

False

Question 40

Fill in the blank: The element with atomic number 1 is __________.

Answer 40

Hydrogen

Question 41

What group in the periodic table contains the Noble gases?

Answer 41

Group 18

Question 42

Which element is represented by the symbol 'Fe'?

Answer 42

Iron

Question 43

What is the most abundant element in the universe?

Answer 43

Hydrogen

Question 44

Identify the element: Atomic number 26.

Answer 44

Iron

Question 45

True or False: Oxygen is a diatomic molecule under standard conditions.

Answer 45

True

Question 46

What is the chemical symbol for Gold?

Answer 46

Au

Question 47

Which element has the highest atomic number that occurs naturally?

Answer 47

Uranium (92)

Question 48

Fill in the blank: The element with the symbol 'Cl' is __________.

Answer 48

Chlorine

Question 49

What is the characteristic of Alkali metals?

Answer 49

They are highly reactive and have one electron in their outer shell.

Question 50

Which element is a liquid at room temperature?

Answer 50

Bromine

Question 51

What is the atomic number of Silicon?

Answer 51

14

Question 52

True or False: All elements in Group 1 are nonmetals.

Answer 52

False

Question 53

What element is known for its use in batteries and has the symbol 'Li'?

Answer 53

Lithium

Question 54

Which element is the lightest noble gas?

Answer 54

Helium

Question 55

What is the chemical symbol for Boron?

Answer 55

B

Question 56

Identify the element: It is a metalloid with the atomic number 14.

Answer 56

Silicon