Chem Review Flashcards
What is the atomic number of an element?
The atomic number is the number of protons in the nucleus of an atom.
True or False: The mass number is the sum of protons and electrons in an atom.
False
Fill in the blank: The __________ is the smallest unit of an element that retains the properties of that element.
atom
What is the chemical formula for water?
H2O
Which subatomic particle has a negative charge?
Electron
What is the difference between an ionic bond and a covalent bond?
An ionic bond involves the transfer of electrons, while a covalent bond involves the sharing of electrons.
True or False: All metals are good conductors of electricity.
True
What is the pH scale used for?
The pH scale is used to measure the acidity or basicity of a solution.
Name the three states of matter.
Solid, liquid, gas
What is the principle of conservation of mass?
The principle states that mass is neither created nor destroyed in a chemical reaction.
What is an isotope?
An isotope is an atom of the same element with a different number of neutrons.
Fill in the blank: The __________ is the region around the nucleus where electrons are likely to be found.
electron cloud
What does the term ‘molarity’ refer to?
Molarity refers to the concentration of a solution expressed as moles of solute per liter of solution.
What is the law of definite proportions?
The law states that a chemical compound always contains its component elements in fixed ratio by mass.
True or False: A catalyst increases the rate of a chemical reaction without being consumed.
True
What is the formula for calculating the number of moles?
Number of moles = mass (g) / molar mass (g/mol)
What is the significance of the periodic table?
The periodic table organizes elements based on their atomic number and properties.
Define oxidation and reduction.
Oxidation is the loss of electrons, while reduction is the gain of electrons.
What is a chemical reaction?
A chemical reaction is a process that involves the transformation of one set of chemical substances into another.
Fill in the blank: The __________ law states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of each gas.
Dalton’s
What is the difference between exothermic and endothermic reactions?
Exothermic reactions release heat, while endothermic reactions absorb heat.
What are valence electrons?
Valence electrons are the electrons in the outermost shell of an atom that are involved in bonding.
True or False: The boiling point of a substance is the temperature at which it changes from liquid to gas.
True
What is the formula for calculating density?
Density = mass/volume
