structure of matter Flashcards
What is the basic unit of matter?
Atom
True or False: Molecules are formed when two or more atoms bond together.
True
Fill in the blank: The __________ is the central part of an atom that contains protons and neutrons.
nucleus
What are the negatively charged particles in an atom called?
Electrons
Which subatomic particle has a positive charge?
Proton
What is the charge of a neutron?
Neutral
Multiple Choice: Which of the following particles determines the atomic number of an element? A) Neutron B) Proton C) Electron
B) Proton
What is an isotope?
Atoms of the same element with different numbers of neutrons.
True or False: The mass number of an atom is the sum of protons and neutrons.
True
What do you call the outermost electrons of an atom?
Valence electrons
Fill in the blank: The __________ model describes the behavior of electrons in atoms as wave functions.
quantum
Multiple Choice: Which of the following is NOT a state of matter? A) Solid B) Liquid C) Air Pressure
C) Air Pressure
What is the primary force that holds atoms together in a molecule?
Chemical bond
True or False: Ionic bonds involve the sharing of electrons.
False
What type of bond is formed when electrons are shared between atoms?
Covalent bond
Fill in the blank: A __________ bond occurs between a metal and a non-metal.
ionic
What is the term used for the representation of a molecule using symbols and lines?
Structural formula
Multiple Choice: Which of the following elements is a noble gas? A) Oxygen B) Helium C) Nitrogen
B) Helium
What is the main difference between a compound and a mixture?
A compound has a fixed composition, while a mixture does not.
True or False: All compounds are mixtures.
False
What is the term for the smallest particle of a compound that retains its chemical properties?
Molecule
Fill in the blank: The __________ theory explains how atoms combine to form molecules.
collision
What is the name of the force that keeps protons and neutrons bound together in the nucleus?
Strong nuclear force
Multiple Choice: Which particle has the least mass? A) Proton B) Neutron C) Electron
C) Electron
What is the atomic mass unit (amu) used to measure?
The mass of atoms and subatomic particles.
True or False: Electrons are found in fixed orbits around the nucleus.
False
What does the term ‘valency’ refer to in chemistry?
The ability of an atom to bond with other atoms.
what is the difference between a mixture and a pure substance?
pure substance only consists of one element or compound. mixtures consist of two or more different substances not chemically bonded together.
classification of matter: pure substances and mixtures
pure substance
- elements
- compiunds
mixtures
- solutions, homogenous mixtures
- solutions, heterogenous mixtures
