RPC

Trigger 1

Matter

• Anything that takes up space and has mass.

• Can be found in different states, such as solid, liquid, and gas.

• Made up of atoms and molecules, which are made up of smaller particles such as protons, neutrons, and electrons

• Plays a crucial role in various fields of study including physics, chemistry, biology, and earth science.

Density, color, and conductivity

Matter can be described by its properties, such as _______,_______, and _________.

Melting, freezing, evaporation, and condensation

Matter can also change from one form to another, through processes such as ________,________,_________, and ___________.

Atoms

• Matter is made up of _________, and these are the basic building blocks of matter.

• Smallest unit of an element that can exist and still retain the properties of that element

Molecules

• All matter, whether a solid, liquid, or gas, is made up of atoms and/or ___________, which are collections of atoms that are held together by chemical bonds.

• Smallest particle of a compound

Atomic physics

The study of atoms and their interactions is known as ____________ the study of atoms and molecules and their interactions is known as physical chemistry.

Element

• An __________ is a pure chemical substance made up of only one type of atom

• Each is unique and has its own distinct properties.

• The basic building blocks of matter and are represented by chemical symbols, such as H for hydrogen and O for oxygen.

118

There are currently ______ known elements, each with its own atomic number, which corresponds to the number of protons in the element's atoms.

Periodic table

Elements are arranged in the _____________, a tabular arrangement of elements according to their atomic number, electron configurations and chemical properties.

Isotope

• Elements can exist in different forms, known as __________, which have the same number of protons but a different number of neutrons

• These _________ of an element have the same chemical properties but may have different physical properties.

Carbon 12

• 6 Electrons

• 6 Protons

• 6 Neutrons

• Nuclear No.:

  6+6=12

• STABLE

Carbon 13

• 6 Electrons

• 6 Protons

• 7 Neutrons

• Nuclear No.:

  6+7=13

• STABLE

Carbon 14

• Because this has six protons, it is still carbon, but the two extra neutrons make the nucleus unstable.

• In order to reach a more stable state, this releases a negatively charged particle from its nucleus that turns one of the neutrons into a proton.

• 6 Electrons

• 6 Protons

• 6 Neutrons

• Nuclear No.:

  6+8=14

• RADIOACTIVE

Carbon-14, C-14, ¹⁴ C or radiocarbon

• A radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.

• Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues to date archaeological, geological and hydrogeological samples

Chemical bonds

The forces that hold atoms together in a molecule.

1. Covalent Bond

2. Ionic Bond

3. Metallic Bond

4. Hydrogen Bond

There are several types of chemical bonds, including:

Electron binding energy

The strength of attachment of an electron to the nucleus is called __________, designated E_b

Greater the total number of electrons

The __________ in an atom, the more tightly each is bound.

Covalent bonds

• Occur when atoms share one or more electrons.

• The atoms involved have a full outer electron shell, which gives them greater stability.

• Found in compounds such as water (H2O) and methane (CH4).

Ionic bonds

• Occur when one atom donates an electron to another atom, creating ions.

• The atoms involved have an unequal number of electrons and protons, which gives them a charge.

• Found in compounds such as sodium chloride (NaCl) and calcium oxide (CaO).

Metallic bonds

• Occur when atoms lose some of their electrons to form a "sea" of electrons that are free to move throughout the metal.

• These bonds are responsible for the characteristic properties of metals, such as their high melting and boiling points, ductility and malleability

Hydrogen Bonds

• The weak chemical bonds between a hydrogen atom and a highly electronegative atom such as nitrogen, oxygen, or fluorine.

• These bonds are relatively weak compared to covalent or ionic bonds and are formed between molecules rather than atoms.

• Play an important role in the properties of many biomolecules such as DNA and proteins.

Greek Atom

• All matter is composed of four substances: AIR, WATER, FIRE AND EARTH modified by four basic essences: wet, dry, hot and cold.

• Used the term “atomos” meaning indivisible.

Dalton Model

• Proposed by John Dalton in 1808

• Element was composed of identical atoms that reacted the same way chemically.

• Elements could be differentiated based on the characteristic of its atomic mass

• Physical combination of one type of atom with another was visualized as being an ball-and-hook affair.

  • Different size balls represent different atom types

  • Different types have different numbers of hooks representing bonding

• Atoms are indivisible and indestructible

• All atoms of a given element are identical in their properties and have the same atomic weight

• Atoms of different elements have different properties and different atomic weights

Compounds

In Dalton’s model, ____________ are formed by the combination of atoms of different elements in fixed ratios

Chemical reactions

In Dalton’s model, ___________ involve the rearrangement of atoms, not the creation or destruction of atoms

Atomic theory

In Dalton’s model, the ____________ provided a theoretical framework for understanding the behavior of elements and their reactions with one another, and laid the foundation for the development of modern chemistry.

Thomson Model

• Proposed by J.J. Thomson in 1897

• The atom is made up of a positively charged sphere with negatively charged electrons scattered throughout

• The electrons are arranged randomly within the sphere

• The overall charge of the atom is neutral because the number of electrons is equal to the number of positive charges

• The electrons are thought to be in constant motion, and can move from one area of the atom to another

• The electrons are held in their positions by electrostatic forces between the negatively charged electrons and the positively charged sphere

• This model is known as the "plum pudding" model.

Rutherford Model

• Proposed by Ernest Rutherford in 1911

  • described the atom as containing a small, dense, positively charged center surrounded by a negative cloud of electrons

• The atom has a small, dense, positively charged nucleus at its center

  • The nucleus contains protons, which have a positive charge

  • Electrons orbit the nucleus in a similar way that planets orbit the sun

• Number of protons in the nucleus determines the atomic number of the element

• The overall charge of the atom is neutral because the number of electrons is equal to the number of protons

• The electrons are held in their positions by the electrostatic force of attraction between the negatively charged electrons and the positively charged nucleus

• Most of the atom is empty space, with the electrons occupying only a small region around the nucleus

• Rutherford called the center of the atom the nucleus.

• This model is known as the "nuclear" model.

Bohr Model

• Proposed by Niels Bohr in 1913

• The atom has a small, dense, positively charged nucleus at its center

• The nucleus contains protons, which have a positive charge, and neutrons which are neutral

• The electrons orbit the nucleus in specific energy levels, or "shells"

  • The energy levels are quantized, meaning that the electrons can only have certain specific energies

• An electron can jump from one energy level to another, but it must absorb or emit a photon with energy equal to the difference in energy between the levels

• The number of electrons in the outermost energy level, or "valence level" determines the chemical properties of the element

• The overall charge of the atom is neutral because the number of electrons is equal to the number of protons

• This model provided a theoretical explanation for the atomic spectra observed in experiments, and was the first theoretical framework which was able to explain the stability of atoms and their spectra.

• Miniature Solar System

Atoms

Are made up of a small, dense nucleus containing positively charged protons and neutral neutrons, surrounded by negatively charged electrons that orbit the nucleus in shells

Atomic number

The number of protons in the nucleus, determines the element to which an atom belongs.

Neutrons

The number of __________ in the nucleus can vary for atoms of the same element, resulting in isotopes.

Valence electrons

• The electrons in the outermost shell of an atom are called __________ and are responsible for the chemical properties of an element.

• The number of __________ determines how an atom will bond with other atoms, and thus its chemical behavior

Shells

• The electrons in an atom are arranged in ________, each can hold a certain number of electrons.

  • For example, the first one holds up to 2 electrons, the second holds up to 8 electrons and so on.

• Within each _______, electrons occupy specific energy levels or orbitals.

1. Proton

2. Neutron

3. Electron

Fundamental Particles of an Atom

Proton

• 1.673 × 10^-27 kg

• 1.00728 amu

• Carries one unit of positive electric charge

• A subatomic particle that is found in the nucleus of an atom.

• Positively charged and has a charge of +1e (one elementary charge).

• The number of this in the nucleus, also known as the atomic number, determines the element to which an atom belongs.

• In a neutral atom this is the same as the number of electrons

  • Determines the number of electrons that orbit the nucleus, as atoms are neutral and thus have an equal number of protons and electrons.

• A composite particle, which means it is made up of other particles, namely two up quarks and one down quark, held together by the strong force.

• Considered as a baryon, which means it belongs to a group of subatomic particles that are made up of three quarks

Quarks

Protons are made up of even smaller particles called _______, held together by the strong nuclear force.

Strong nuclear force

• One of the four fundamental forces of nature, and it is responsible for holding the protons and neutrons together in the nucleus

• Much stronger than the electromagnetic force but it only acts over very short distances.

• Responsible for binding protons and neutrons together to form the nuclei of atoms, and it is responsible for the stability of atomic nuclei.

Neutron

• 1.675 × 10^-27 kg

• 1.00867 amu

• Carries no charge; it is electrically neutral

• Subatomic particles that are found in the nucleus of an atom.

• They have a neutral charge, meaning they have no electrical charge.

• They are slightly heavier than protons

• Play a key role in the stability of atoms, as the number of __________ can vary for atoms of the same element, resulting in isotopes

• Play a significant role in nuclear reactions, nuclear fission and nuclear fusion, as they are involved in the binding energy that holds the nucleus together

• Also a composite particle, which means it is made up of other particles, namely one up quark and two down quarks, held together by the strong force

• Considered as a baryon, which means it belongs to a group of subatomic particles that are made up of three quarks

Electron

• Carries one unit of negative electric charge

• Revolve around the nucleus at fixed orbits

• Mass = 9.1 × 10^-31 kg

• Since mass is too small to measure, its mass is expressed in atomic mass unit (amu)

  • 1 amu = ½ mass og a carbon-12 atom

• Mass = 0.000549 amu

  Subatomic particles that are found outside the nucleus of an atom.

• Negatively charged and have a charge of -1e (one elementary charge).

• Orbit the nucleus in shells.

  • The outermost shell is called the valence shell and is responsible for the chemical properties of an atom.

• Arranged in shells, each shell can hold a certain number of electrons.

• Are point particles, as they have no known subatomic structure and are held in the orbits around the nucleus by the electromagnetic force.

• Play a key role in the chemical reactions and electricity

  • As they are involved in the transfer of electrons in chemical reactions and the flow of electric current in conductors.

Electron configuration

The arrangement of electrons in an atom is known as its ____________

2n²

Maximum Electrons per shell (formula)

• where n is the shell number

Distance

The number of electrons that can exist in each shell increases with the __________ of the shell from the nucleus

Z

Atomic number or the number of protons in an atom

A

Atomic mass or the number of protons and neutrons

Not equal

The atomic mass number and the precise mass of an atom are __________

Basic force of nature

A __________ is a fundamental interaction that governs the behavior of matter and energy in the universe.

1. Gravity,

2. Electromagnetism,

3. The strong nuclear force, and

4. The weak nuclear force.

Four known basic forces of nature:

Gravity

• Force that attracts any two objects with mass towards each other.

• It is the force that keeps us on the ground and keeps planets in orbit around stars.

• The strength of this between two objects is directly proportional to the mass of the objects and inversely proportional to the square of the distance between them.

• Caused by the presence of mass or energy

• According to the theory of general relativity, proposed by Albert Einstein:

  • This is not a force between masses, but the curvature of spacetime caused by the presence of mass or energy.

  • This theory explains the behavior of this very well, including phenomena such as black holes and the expansion of the universe.

Electromagnetism

• Force that causes charged particles to interact with each other.

• Responsible for the behavior of electric charges, and it also explains the behavior of magnets.

  • The electric current creates a magnetic field around the wire, which causes it to act like a magnet.

  • The strength of the magnetic field is directly proportional to the amount of current flowing through the wire, and the direction of the magnetic field is determined by the direction of the current

Electromagnetic Force

• Binds electrons to the atom

• Force of the electrons and protons

Centripetal force

• “Center-seeking” force

• Attracts the electron towards the nucleus

• The force that keep electrons in orbit

Centrifugal force

• “Flying-out-from-the-center” force

• Force of electron caused by its velocity

Weak Nuclear Force

• Responsible for certain types of radioactive decay, such as beta decay.

• Much weaker than the strong nuclear force but it still plays an important role in certain natural processes.

• One of the key characteristics of this is that it only acts over very short distances, typically on the order of 10^-18 meters.

  • This means that it cannot hold atomic nuclei together like the strong nuclear force, but it can cause certain types of nuclei to decay.

• Responsible for the conversion of a neutron into a proton, which releases an electron and an antineutrino.

  • This process is called beta decay, and it is one of the ways that atomic nuclei can change to form different elements

Antineutrino

• A subatomic particle that is the antiparticle of the neutrino.

• Similar to the neutrino in that it has no charge and very little mass, but it has opposite properties in other regards.

  • Like the neutrino, this is affected only by the weak nuclear force and gravity and does not interact strongly with other matter, making it difficult to detect.

• Are also produced in nuclear power plants and in the sun, through nuclear reactions that take place there.

Isobar

Atomic nuclei that have the same atomic mass number but different atomic numbers

Isotone

Atoms that have the same number of neutrons but different numbers of protons

Isomers

Have the same atomic number and the same atomic mass number.

Chemical compound

A ____________ is any quantity of one type of molecule

Ionization

• Removal of an orbital electron from an atom.

• If an atom has an extra electron or has had an electron removed, it is said to be ionized.

Zero

In their normal state atoms are electrically neutral; the electric charge on the atom is ______.

Dmitri Mendeleev

A Russian scholar, that showed if the elements were arranged in order of increasing atomic mass, a periodic repetition of similar chemical properties occurred.

Eight

No outer shell can contain more than _______ electrons.

Group

Determined by the number of electrons in the outermost shell

Period

Determined by the number of outermost electron shells

Greater

• In all except the lightest atoms, the number of neutrons is always _______ the the number of protons.

• The larger the atom, the ________ the abundance of neutrons over protons.