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WorksheetsChemistry Worksheet Questions Extraction
Total questions: 50
Worksheet time: 25mins
Which atomic model describes electrons as existing in regions called orbitals?
Bohr Model
Quantum Mechanical Model
Plum Pudding Model
Rutherford Model
What is the group and period of an element with electron configuration 1s² 2s² 2p⁶ 3s²?
Group 2 Period 3
Group 3 Period 2
Group 8 Period 2
Group 2 Period 2
How many electrons are present in a neutral atom with a full K and L shell?
8
10
18
2
Which of the following sublevels is correctly written?
2p7
3d9
4g1
1d2
An electron with n = 4, l = 0, ml = 0, ms = −½ is found in which orbital?
4s
4p
4d
3s
Which of the following sets of quantum numbers is invalid?
n = 3, l = 1, ml = 0, ms = +½
n = 2, l = 2, ml = −1, ms = +½
n = 4, l = 3, ml = +3, ms = −½
n = 1, l = 0, ml = 0, ms = +½
What orbital corresponds to n = 3 and l = 2?
3s
3p
3d
2d
What quantum number determines the shape of the orbital?
n
l
ml
ms
What is the correct electron configuration for nitrogen (Z = 7)?
1s² 2s² 2p³
1s² 2s¹ 2p⁴
1s² 2s² 2p⁵
1s² 2s² 2p⁶
Which of the following elements has a partially filled d-orbital?
Magnesium
Copper
Neon
Oxygen
What sublevel is filled immediately after 3p in the Aufbau principle?
3d
4s
4p
3f
Which element has the configuration [Ne] 3s² 3p⁴?
Phosphorus
Sulfur
Chlorine
Argon
What is an anion?
A positively charged ion
A negatively charged ion
A neutral molecule
An ion that has lost protons
What type of ion is formed when an atom gains electrons?
Anion
Proton
Cation
Neutron
Why does chlorine gain one electron?
To become a cation
To achieve full outer shell
Because it is a metal
To increase atomic mass
Which is correct about aluminum ion formation?
It gains 3 electrons to form Al³−
It loses 3 electrons to form Al³+
It gains 2 electrons to form Al²−
It doesn’t form ions
What is the correct ion formed by oxygen?
O⁺
O⁻
O²⁺
O²⁻
What is the correct formula for the compound between K⁺ and O²⁻?
KO
K₂O
KO₂
K₃O
What is the name of the compound Na₂S?
Sodium monosulfide
Sodium sulfate
Disodium sulfide
Sodium sulfide
What is the correct formula for magnesium and chlorine?
MgCl
Mg₂Cl
MgCl₂
Mg₂Cl₂
Which of the following is correctly matched?
Calcium fluoride – CaF₂
Calcium fluoride – CaF
Calcium fluoride – Ca₂F
Calcium fluoride – Ca₂F₃
What is the formula of the ionic compound formed by aluminum and sulfur?
AlS
Al₂S
Al₂S₃
Al₃S₂
Which pair forms Li₃N?
Lithium and nitrogen
Lithium and oxygen
Lithium and carbon
Lithium and chlorine
What is the correct formula for barium and fluorine?
BaF
BaF₂
Ba₂F
Ba₂F₃
How many electrons surround phosphorus in PF₅?
8
10
12
6
Which bond is likely formed between two atoms with equal electronegativity?
Ionic
Polar covalent
Nonpolar covalent
Hydrogen
Which substance conducts electricity in water?
Ethanol
NaCl
Sugar
Oil
Why is NaCl soluble in water?
Water is nonpolar
NaCl dissociates into ions
NaCl molecules stay intact
Ions bind together in water
Which compound is ionic?
CO
H₂O
Na₂O
CH₄
How is a cation formed?
Gaining a neutron
Gaining an electron
Losing an electron
Losing a proton
What is formed when hydrogen bonds with carbon?
Water
Hydrocarbon
Salt
Ether
What property describes a volatile compound?
Does not mix with air
Turns to gas easily
Freezes at room temp
Burns slowly
Gasoline is dangerous to smoke around because it is:
Viscous
Flammable
Inert
Odorless
Which of the following is true about organic compounds?
Made of metals
Contain carbon and hydrogen
Only exist in lab
Do not form chains
Which solvent is commonly used to remove paint?
Vinegar
Water
Kerosene
Ammonia
Which hydrocarbon contains a double bond?
Ethyne
Propane
Ethene
Methane
If a hydrocarbon has single bonds only, it belongs to which group?
Alkynes
Alkenes
Alkanes
Aromatics
How many particles are in one mole of a substance?
6.02 × 10²³
3.01 × 10²³
1.00 × 10²³
6.02 × 10²⁴
What unit is used to count particles?
Gram
Mole
Liter
Meter
How many hydrogen atoms are in one (NH₄)₃PO₄ molecule?
4
6
9
12
What is the mass of one mole of a compound called?
Empirical mass
Atomic number
Molar mass
Chemical weight
How many moles are in 44 g of CO₂? (M = 44 g/mol)
1
2
0.5
4
What is the molar mass of H₂O?
18 g/mol
20 g/mol
10 g/mol
22 g/mol
What is the percent by mass of hydrogen in H₂O?
10%
11.1%
8.9%
12%
What is the molar mass of CH₃COOH (acetic acid)?
60 g/mol
45 g/mol
75 g/mol
90 g/mol
What is the percent by mass of carbon in CO₂? (M = 44 g/mol)
12%
27%
50%
27.3%
If the empirical formula is CH₃ and the molar mass is 30 g/mol, what is the molecular formula?
CH₃
C₂H₆
CH₄
C₃H₆
A compound contains 85.7% C and 14.3% H. What is the empirical formula?
CH₄
C₂H₆
CH₂
C₆H₁₂
The empirical formula of a compound represents:
Actual number of atoms
Simplest whole-number ratio of atoms
Exact arrangement of atoms
Molar mass of the compound
50. What does the law of conservation of mass state?
Atoms can disappear
Energy is conserved
Mass is created
Mass is neither created nor destroyed
