WorksheetsChemistry Competition 2021
Total questions: 35
Worksheet time: 15mins
Which of the following phases of matter as the highest kinetic energy (besides plasma)?
Gas
Liquid
Solid
Which of the following states of matter has the highest potential energy?
Gas
Liquid
Solid
A physical substance that has mass and occupies space is called what?
Radiation
Matter
Darkmatter
Which type of chemical formula always matches its structural formula (diagram)?
Molecular
Empirical
Which of the following are characteristics of the ball-and-stick model?
Proportional atom sizes
Equal atom sizes
Bonds shown as cylindrical connections
Atoms are spherical
What is true of physical changes?
They are reversible
They are chemical reactions
They change a substance's composition
They change a substance's phase
Select all that are physical changes
Water boiling
Food digesting
Wood cutting
Fuel burning
Most chemical reactions are
irreversible
reversible
What is true of chemical changes?
They are chemical reactions
They cannot be readily measured
Most are irreversible
Most are reversible
Select all that are chemical changes
Food digesting
Salt formation
Water freezing
Molten metal solidifying
Select the most approriate units for measuring mass
Pounds (lbs.)
Grams (g)
Kilograms (kg)
Tons (t)
How does weight differ from mass?
No difference
Mass is weight affected by gravity
Weight is mass affected by gravity
Which best describes the relationship between mass, density, and volume?
Mass ÷ Density = Volume
Mass ÷ Volume = Density
Density ÷ Mass = Volume
Volume ÷ Mass = Density
How do molecules and compounds differ?
No difference
Molecules are a type of compound
Compounds are a type of molecule
Generally, how do like and opposite charges interact?
Like charges attract, opposite charges repel
Both like and opposite charges repel
Both like and opposite charges repel
Like charges repel, opposite charges attract
What subatomic particles are found in the nucleus?
Protons
Neutrons
Electrons
Which atomic model is currently the most accurate?
Bohr Model (Planetary Model)
Rutherford Model (Nuclear Model)
Schrodinger Model (Electron Cloud Model)
Democritus Model (Solid Sphere Model)
What are the only 2 possibilities of electrons for a full valence shell?
1
2
4
8
What do the P, S, D, and F blocks refer to?
Types of atom shapes
Types of orbitals
Types of reactions
Types of nuclei
The # of which subatomic particle determines an element's identity?
Protons
Neutrons
Electrons
Gold has an atomic number of 79 and an average atomic mass of 197, how many electrons does gold have?
118
197
79
315
The chalcogens group is located right next to the noble gases, how many valence electrons does its elements have?
5
6
7
8
Which of the following elements would be the most reactive?
Carbon
Fluorine
Gold
Nickel
All of the following periodic table trends increase upwards and rightwards EXCEPT?
Electronegativity
Ionization energy
Atomic radius
Electron affinity
How are cations and anions different?
Cations are -, anions are +
Anions are -, cations are +
Both are +
Both are negative -
How do ionic bonds exist?
One atom gives an electron to the other, but is still attracted to it
Both atoms share an electron pair
Atoms share a common pool of electrons
How do polar covalent bonds exist?
Electron pair is equally shared
Electron pair is not at all shared
Electron pair is unequally shared
What type of bonds do salts have?
Covalent
Ionic
Metallic
What metals are usually found in salts?
Alkali metals
Transition metals
Alkaline earth metals
Post-transition metals
What does the 1st Law of Thermodyamics say?
Some energy is wasted every time a transfer occurs
Less energy is wasted as atoms become less energized
Energy is always transferred; never created or destroyed
What does the 2nd Law of Thermodyamics say?
Some energy is wasted every time a transfer occurs
Less energy is wasted as atoms become less energized
Energy is always transferred; never created or destroyed
What does the 3rd Law of Thermodyamics say?
Some energy is wasted every time a transfer occurs
Less energy is wasted as atoms become less energized
Energy is always transferred; never created or destroyed
Which thermodynamic law makes reaching absolute zero impossible?
1st Law of Thermodynamics
2nd Law of Thermodynamics
3rd Law of Thermodynamics
Which thermodynamic law refers to enthalpy?
1st Law of Thermodynamics
2nd Law of Thermodynamics
3rd Law of Thermodynamics
Tiebreaker: Which non-metal shares the same number of valence electrons as all the alkali metals?
Chlorine
Hydrogen
Lithium
Carbon
