Flashcards
What is the atomic number of an element?
The number of protons in the nucleus of an atom.
True or False: The mass number of an atom is the sum of its protons and electrons.
False
Fill in the blank: The formula for calculating the number of neutrons is _____.
Mass number - Atomic number
What is the chemical symbol for sodium?
Na
What is the pH of a neutral solution?
7
Which of the following is a noble gas? (a) Oxygen (b) Helium (c) Nitrogen
b) Helium
What is the name given to the vertical columns in the periodic table?
Groups
True or False: Metals tend to gain electrons during chemical reactions.
False
What is the main component of air?
Nitrogen
Fill in the blank: The process of a liquid turning into a gas is called _____.
Evaporation
What is the formula for calculating the number of moles?
Number of moles = Mass (g) / Molar mass (g/mol)
Which type of bond involves the sharing of electron pairs?
Covalent bond
What is the relative atomic mass of carbon?
12
True or False: Ionic compounds conduct electricity when solid.
False
What is the definition of an isotope?
Atoms of the same element with different numbers of neutrons.
Which of the following is an alkali metal? (a) Magnesium (b) Potassium (c) Calcium
b) Potassium
Fill in the blank: The process of a gas turning into a liquid is called _____.
Condensation
What do you call a substance that speeds up a chemical reaction?
Catalyst
What is the chemical formula for water?
H2O
True or False: Acids have a pH less than 7.
True
What is the term for a solution that contains the maximum amount of solute that can be dissolved?
Saturated solution
What is the process called when a solid changes directly to a gas?
Sublimation
Fill in the blank: The periodic table is arranged by increasing _____.
Atomic number
Which type of reaction involves the breaking down of a compound into simpler substances?
Decomposition reaction
What is the formula for calculating concentration?
Concentration (g/dm³) = Mass of solute (g) / Volume of solution (dm³)
True or False: The law of conservation of mass states that mass is created in a chemical reaction.
False
What is an example of a physical change?
Melting ice
What is the chemical symbol for chlorine?
Cl
Fill in the blank: An endothermic reaction absorbs _____.
Energy
What is the main gas produced during respiration?
Carbon dioxide
What is the name of the process by which plants make their own food?
Photosynthesis
True or False: Bases react with acids to form salts and water.
True
What is the term for the measure of how much solute is dissolved in a solvent?
Concentration
What type of chemical reaction is represented by the equation: A + B → AB?
Synthesis reaction
What is the principle behind the conservation of mass?
Mass cannot be created or destroyed in a chemical reaction.
Fill in the blank: The main gas responsible for global warming is _____.
Carbon dioxide
What does the term ‘exothermic’ refer to?
A reaction that releases heat.
What is the formula for calculating energy change?
Energy change = Energy of products - Energy of reactants
True or False: All chemical reactions require energy to start.
True
What is the process of separating a mixture by heating and cooling called?
Distillation
What is the chemical formula for table salt?
NaCl
Which of the following is a characteristic of metals? (a) Brittle (b) Good conductors of heat (c) Low density
b) Good conductors of heat
Fill in the blank: The smallest particle of an element is called an _____.
Atom
What is the term for a mixture that has uniform composition throughout?
Homogeneous mixture
