Chemistry Flashcards
(30 cards)
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 the number of protons and neutrons in an atom.
True
Fill in the blank: An ion is an atom that has gained or lost ______.
electrons
What is the chemical formula for water?
H2O
Which of the following is a noble gas? (A) Oxygen (B) Helium (C) Nitrogen
B) Helium
What is the pH range of acids?
The pH range of acids is less than 7.
Define a covalent bond.
A covalent bond is a chemical bond formed by the sharing of electrons between atoms.
What is the periodic table?
The periodic table is a tabular arrangement of the chemical elements, organized by increasing atomic number.
True or False: Metals are generally good conductors of electricity.
True
What do you call a substance made of only one type of atom?
An element
What is the process of a liquid turning into a gas called?
Evaporation
Fill in the blank: A ______ is a mixture that has a uniform composition throughout.
solution
What is the main characteristic of alkali metals?
Alkali metals are highly reactive and have one electron in their outermost shell.
What happens during a chemical reaction?
During a chemical reaction, bonds between atoms are broken and new bonds are formed, resulting in the creation of new substances.
Which particle has a negative charge?
Electron
True or False: All chemical reactions require energy.
True
What is an endothermic reaction?
An endothermic reaction is a chemical reaction that absorbs energy from its surroundings.
What determines the reactivity of an element?
The number of electrons in the outer shell determines the reactivity.
What is the term for a solution that has a pH greater than 7?
A base
Which of the following is an example of a physical change? (A) Burning wood (B) Melting ice (C) Rusting iron
B) Melting ice
What is the law of conservation of mass?
The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction.
What is an isotope?
An isotope is a variant of a chemical element that has the same number of protons but a different number of neutrons.
Fill in the blank: The ______ is the smallest unit of an element that retains the properties of that element.
atom
What is the difference between a compound and a mixture?
A compound is a substance formed when two or more elements chemically combine, while a mixture is a combination of two or more substances that are not chemically bonded.
