Atoms Flashcards
What makes up all living matter?
Atoms make up all living matter.
What are atoms made up of?
Atoms are made up of subatomic particles like protons, neutrons, and electrons, empty space
How are elements arranged on the periodic table?
Elements on the periodic table move in columns and rows. Columns go downwards and up, and rows go side to side.
What are the three main groups of the periodic table?
The three main groups of the periodic table are metals, metalloids, and nonmetals.
What are rows in the periodic table called?
Rows in the periodic table are called periods.
What do elements in a period have in common?
Each element in a period has the same number of occupied electron shells.
What are columns in the periodic table called?
Columns in the periodic table are called groups.
Where are protons and neutrons located?
Protons and neutrons are located in the nucleus.
What do elements in a group have in common?
Each element in a group has the same number of valence electrons.
What is the size and composition of atoms?
Atoms are very small and are mostly empty space.
What is the charge and mass of protons?
Protons are positively charged, 1 amu, located in the nucleus.
What is the charge and mass of neutrons?
Neutrons have no charge, 1 amu, and are located in the nucleus.
What is the charge and mass of electrons?
Electrons have a negative charge, 0 amu, and are located in shells that orbit the nucleus.
What does the atomic number represent?
The atomic number tells us the number of protons in a nucleus.
What does the mass number represent?
The mass number tells us the number of protons and neutrons in a nucleus.
Do electrons contribute much to the overall mass of the atom?
Electrons are very small and do not contribute much to the overall mass of the atom.
Who invented the solid sphere model and when?
John Dalton invented the solid sphere model in 1803.
What did JJ Thompson discover?
JJ Thompson discovered electrons and created the plum pudding model in 1904.
What did Ernest Rutherford discover?
Nuclear model in 1911
-discovered that an atom is mostly empty space
-positively charged nucleus
What did Niels Bohr discover?
Niels Bohr discovered the planetary model in 1913, stating that electrons move in electron shells.
What did Erwin Schrödinger invent?
Erwin Schrödinger invented the Quantum model, stating that electrons do not move in set paths.
Who discovered neutrons?
James Chadwick discovered the neutrons.
What is the formula for calculating the number of electrons in each shell?
The formula is 2n squared.
How many electrons can the first three shells hold?
The first shell can hold 2 electrons, the second shell can hold 8, and the third shell can hold 18.
What do electrons prefer in terms of energy state?
Electrons prefer lower state energy.
What is an isotope?
An isotope is when an atom has the same amount of protons while the neutrons change.
What is an ion?
An ion is a particle that loses or gains electrons.
What is a cation?
A cation is when an atom gives away electrons. (looses)
What is an anion?
An anion is when an atom takes electrons.
What is an element?
atom adds or removes protons to change elements, pure substance
What is a molecule?
A molecule is when 2 or more atoms chemically bond together.
What does the Bohr model state about electron shells?
The Bohr model states that the innermost shells can only take 2 electrons while the next can take 8 and 18 electrons.
What is the octet rule?
The octet rule states that all atoms want to have a full eight electrons in their outer shell to be stable.
Why are some isotopes unstable?
Some isotopes are unstable because the neutrons change, causing one of the neutrons to convert into protons.
How do you calculate the relative atomic mass?
To calculate the relative atomic mass, multiply the mass number of each isotope by its relative abundance, sum these products, and then divide by 100.
What makes nuclei in most atoms stable?
Nuclei in most atoms are stable if the protons and neutrons hold together.
What are unstable isotopes called?
Isotopes that are unstable decay to form other elements called radioisotopes.
What is nuclear radiation?
Energy emitted by radioactive substances is called nuclear radiation as it comes from the nucleus.
What did Rutherford show about nuclear radiation?
Rutherford showed that there were 3 different types of nuclear radiation: alpha, beta, and gamma rays.
What do alpha particles contain?
Alpha particles contain helium nuclei.
What are the characteristics of alpha particles?
Alpha particles have 2 protons and 2 neutrons, contain a positive charge, and cannot travel easily through materials.
What can stop alpha particles?
Alpha particles can be stopped by paper and skin.
What damage can alpha particles cause?
Alpha particles cause serious damage if inhaled.
What are beta particles similar to?
Beta particles have the same mass and size as electrons.
What can beta particles penetrate and not penetrate?
Beta particles can penetrate thin layers of skin and damage living tissue but cannot penetrate plastic, wood, or aluminum.
What are gamma rays?
Gamma rays are bursts of energy released after alpha or beta particles are emitted.
What can stop gamma rays?
Gamma rays can only be stopped by a thick shield of lead or concrete.
What is the charge of gamma rays?
Gamma rays have no charge.
