C1 Flashcards
What are the three states of matter?
Solid, liquid, and gas.
True or False: In a solid, particles are far apart and move freely.
False.
Fill in the blank: The __________ model describes the atom as having a nucleus surrounded by electrons.
Bohr.
What is an atom?
The smallest unit of a chemical element, consisting of a nucleus and electrons.
What are the particles that make up an atom?
Protons, neutrons, and electrons.
What charge do protons carry?
Positive charge.
What is an ion?
An atom or molecule that has gained or lost one or more electrons, resulting in a net charge.
True or False: Isotopes of an element have the same number of protons but different numbers of neutrons.
True.
What is the atomic number?
The number of protons in the nucleus of an atom.
Multiple Choice: Which of the following is a characteristic of gases? A) Definite shape B) Definite volume C) Compressible D) Rigid structure
C) Compressible.
What is the relative mass of an electron compared to a proton?
Much smaller, approximately 1/1836 of a proton.
Fill in the blank: The __________ is the central part of an atom that contains protons and neutrons.
nucleus.
What distinguishes one element from another?
The number of protons in the nucleus.
True or False: An element can have more than one isotope.
True.
What is the mass number of an atom?
The total number of protons and neutrons in the nucleus.
Multiple Choice: Which particle has no charge? A) Proton B) Electron C) Neutron D) All of the above
C) Neutron.
What happens to the particles in a substance when it is heated?
They gain energy and move faster.
Fill in the blank: An atom that has lost an electron becomes a __________.
cation.
What is the difference between a cation and an anion?
A cation is positively charged, while an anion is negatively charged.
What are the two main types of isotopes?
Stable isotopes and radioactive isotopes.
True or False: The history of the atom includes models from Democritus to the modern quantum model.
True.
What is the significance of John Dalton’s atomic theory?
It proposed that matter is made up of indivisible atoms and laid the groundwork for modern chemistry.
What discovery did J.J. Thomson make about the atom?
He discovered the electron.
Fill in the blank: The __________ model of the atom is often described as a ‘plum pudding’ model.
Thomson.
What is the primary reason for the existence of isotopes?
Variation in the number of neutrons in the nucleus.
What is the term for the process by which a substance transitions from a solid to a liquid?
Melting.
