Deck 1 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 is the sum of protons and neutrons in an atom.
True
Fill in the blank: The chemical formula for water is ____.
H2O
What is an ion?
An atom or molecule that has a net electric charge due to the loss or gain of one or more electrons.
What is the pH scale used for?
To measure the acidity or alkalinity of a solution.
What is a catalyst?
A substance that increases the rate of a chemical reaction without being consumed.
What is the formula for calculating density?
Density = Mass / Volume
True or False: All alkali metals are found in Group 1 of the periodic table.
True
What is the process of a solid turning directly into a gas called?
Sublimation
What is the principle behind the law of conservation of mass?
Mass is neither created nor destroyed in a chemical reaction.
What do we call a solution that has a pH of 7?
Neutral solution
Fill in the blank: The chemical symbol for sodium is ____.
Na
What is an exothermic reaction?
A reaction that releases energy in the form of heat.
What is the main component of natural gas?
Methane (CH4)
True or False: Acids taste bitter.
False
What is the term for a substance that increases the concentration of hydrogen ions in a solution?
Acid
What is the formula to calculate the number of moles?
Moles = Mass (g) / Molar Mass (g/mol)
What do you call the horizontal rows in the periodic table?
Periods
What is the difference between an element and a compound?
An element consists of one type of atom, while a compound consists of two or more different types of atoms chemically bonded together.
What is the name of the gas released during photosynthesis?
Oxygen (O2)
Fill in the blank: The process of breaking down glucose to release energy is called ____.
Cellular respiration
What is the term for the amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius?
Calorie
True or False: Noble gases are highly reactive.
False
What is a combustion reaction?
A chemical reaction that occurs when a substance combines with oxygen, releasing energy in the form of light or heat.
What is the law of definite proportions?
A chemical compound always contains its component elements in fixed ratio by mass.
What is the main characteristic of metals?
They are good conductors of heat and electricity.
What is the term for the energy required to break the bonds in a chemical reaction?
Activation energy
