Chem 2 Flashcards
Who proposed the first atomic theory?
John Dalton
What is the basic unit of matter?
Atom
True or False: All atoms of a given element are identical.
True
What particles are found in the nucleus of an atom?
Protons and neutrons
Fill in the blank: The negatively charged particle in an atom is called a __________.
Electron
What is the charge of a proton?
Positive
What is the difference between isotopes?
Isotopes have the same number of protons but different numbers of neutrons.
What is the pH scale used to measure?
Acidity or alkalinity of a solution
What is the pH of pure water?
7
True or False: An ion is an atom that has gained or lost electrons.
True
What is a cation?
A positively charged ion
What is an anion?
A negatively charged ion
Which scientist discovered the electron?
J.J. Thomson
Fill in the blank: The reactivity series ranks metals based on their __________.
Reactivity
What is the most reactive metal in the reactivity series?
Potassium
True or False: Metals are generally more reactive than non-metals.
False
What is the atomic number of an element?
The number of protons in its nucleus
What do we call atoms of the same element with different masses?
Isotopes
Which particle determines the identity of an element?
Proton
What is the formula for calculating pH?
pH = -log[H+]
In which part of the atom are electrons located?
Electron cloud or energy levels
Fill in the blank: The most stable configuration of electrons in an atom is called the __________.
Ground state
Which element has the atomic symbol ‘O’?
Oxygen
What does a pH less than 7 indicate?
Acidic solution
