Explain plasma phase
The plasma phase only exists at high temperatures. The sun and other stars, as well as much of the intergalactic matter, are in the plasma phase. In the plasma phase, matter consists of POSITIVE ions (atoms that are missing some electrons) and free electr
In all phases of matter, the atoms are constantly in ______
In all phases of matter, the atoms are constantly in motion
Explain the solid phase
In the solid phase, atoms and molecules vibrate at fixed positions.
Explain the liquid phase
If the rate of molecular vibration is increased enough, molecules will shake apart and wander throughout the material, moving in non-fixed positions. The material is no longer fixed but takes the shape of its container. This is the liquid phase.
Explain the gaseous phase
If more energy is put into the material so that the molecules move about at even GREEEAATTTER rates, they break away from one another and assume the gaseous phase.
Explain how substances can be transformed from one phase to another
All substances can be transformed from one phase to another. We saw this with H2O. When it is solid, it is ice. If we head the ice, the increased molecular motion jiggles the molecules out of their fixed positions, and we ahve water. If we heat the water
Explain a bond
Attraction between a proton and an electron is called a bond between atoms which forms a molecule. For example, 2 atoms can be held together by the sharing of electrons (covalent bond). Atoms can also be held together when electrons are transferred betwee
How does the size of the nucleus compare with the size of the atom? How about the electron?
The nucleus occupies any tiny amount of the atomic volume in an atom. But electrons, on the other hand, form a kind of cloud as they cruise throughout the atom. Compressing this atom could take great energy and means that when two atoms come together, the
Are we mostly empty space? How do we keep from falling through things as the floor?
We and the solid floor are mostly empty spare, but, because the forces of repulsion keep atoms from caving in on one another under pressure, we don't fall through the floor.
The shell model of the atom
To explain how atoms of different elements interact to form compounds, scientists have produced the shell model of the atom. Electrons are pictures as orbiting spherical shells around the nucleus. Each shell has its own capacity for electrons.
What determines properties such as melting and freezing temperatures, electrical conductivity, taste, texture, appearance, and color of the substance?
The arrangement of electrons around the nucleus dictate properties, such as melting and freezing temperatures, electrical conductivity, taste, texture, appearance, and color of substances.
Periodic Table
Chart that lists atoms by their atomic number and by their electron arrangement. As you read across from left to right, each element has one more proton and electron than the preceded elemtns. As you read down, each element has one more shell than the ele
How do elements in the same column relate?
Element in the same column are said to belong to the same GROUP of elements and elements of the same group have similar chemical properties because their outermost electrons are arranged in similar fashion.
How many phases does matter exist in?
4
Deuterium
When, for example, a normally single proton hydrogen atom is accompanied by a neutron. This atom is an ISOTOPE OF HYDROGEN (think of a single small, weird person in a group of business men)
Isotope Tritium
When, in certain elements, EVERY ATOM has a variety of isotopes. (Think of a BUNCH of different variety of people all working in a post office)
Atomic Number
Atoms are classified by atomic number. It's the number of protons in the nucleus.
Electrical charge come in two kind; what are they?
Positive and negative
Inside the nucleus, what are protons held together held together by?
Inside the nucleus, protons are held together by a strong nuclear force
Electrons
Electrons that orbit the nucleus are the same kind of electrons that flow in the wires of electric circuits. They are negatively charged subatomic particles. In electrically neutral atom, the number of negatively charged electrons equals the number of pos
Ion
Atom that has a number of electrons which is more, or less, than the number of protons in an atom. This atom is no longer neutral and has a net charge
What prevents the close packing of nuclei?
Huge electrical forces of repulsion prevent close packing of nuclei (plural of nucleus) because each is electrically charged and repels the other nuclei.
When are the nuclei of atoms ARE smashed together?
Only under special circumstances are the nuclei of two or most atoms smashed into contacts. When this happens, the violent reaction known as a NUCLEAR FUSION takes place. Fusion occurs in the core of the sun and in a hydrogen bomb.
Nucleons
The principal building blocks of the nucleus are nucleons. Nucleons in an electrically neutral state re nuetrons. Nucleons in the electrically charged state are called protons. All neutrons and protons are IDENTICAL
How do atoms differ from one another?
Atoms differ from one another by their # of protons. Atoms with the SAME number of protons belong to the SAME element.
Isotope
Atoms of the same element having a different number of neutrons are called isotopes of that element
Everything you feel, smell, taste, touch, and hear in the world is made up of ______
atoms
Element
made up of atoms of the same kind
How many elements are currently known?
115
99% of the material on Earth is formed from what
formed from only about a dozen of the elements
What are living things primarily composed of
Living things are composed of primarily 5 elements: oxygen, hydrogen, carbon, nitrogen, and calcium
What are the 16 most common elements on Earth?
aluminum, calcium, carbon, chlorine, fluorine, silicone, sodium, titanium, hydrogen, iron, magnesium, nitrogen, oxygen, phosphorous, potassium, sulfur
What element are more than 90% of the known universe are?
Over 90% of the atoms in the known universe are hydrogen. Helium makes up most of the other atoms in the universe
What are the atoms a result of
The heaviest elements were formed by supernovas (huge stars) exploding and imploading and when stars collided. Nearly all the elements are a result of stars that exploded long before the solar system came in to being
How old are atoms?
Atoms are older than the materials they compose. Most atoms are, at least, as old as the sun and Earth
Explain what happens when you break in and exhale atoms
When you breath, only some of the atoms you inhale are exhaled in your next breath. The remaining atoms are taken into your body to become part of you. Most leave your body sooner or later to become part of everything else
What can be side about the size of atoms
There are more atoms in a thimbleful of water than there are drops of water in the world's lakes and rivers
Explain atom's movement
Atoms are always moving and moving from one place to another. In solids, the rate of migration is low; in liquids, the rate of migration is greater; in gases; migration is greatest. Proof of atoms constantly migrating is chemicals being spilt into the oce
How long does it take for one of your breaths to become evenly mixed in the atmosphere?
It takes about 6 years for one of your breaths to become evenly mixed in the atmosphere. At this point, every person in the world inhales an average of one of your exhaled atoms in a single breath. You have a butt-load of atoms in you that were once in th
Why can't atoms be seen?
Atoms are too small to be seen in visible light because the atoms are smaller than the wavelengths of visible light. The size of a particle must be larger than the wavelength of visible light to be seen. More direct evidence of atoms exists today form vie
Brownian Motion
The perceptual jiggling of particles that are just large enough to be seen. Results from motion of neighboring atoms and molecules
Molecule
Atoms can combine to form larger particles called molecules. A molecule is 2 or more atoms of the same or different elements bonded to form a larger particle.
DNA
The double helix of deoxyribonucleic acid is composed of millions of atoms and is the blueprint of life.
Does matter contain all the same kind of molecules or not?
Matter may contain all the same kind of molecules, or it may be a mixture of different kinds of molecules
Is all matter made of molecules or atoms?
Not all matter is made of molecules. Metals and crystalline minerals (table salt) are made of atoms that are NOT joined in molecules
Are atoms and molecules too small to be seen with optical microscopes?
Like atoms, molecules are too small to be seen with optical microscopes EXCEPT DNA
Explain how we can smell perfume
We are able to detect molecules through our sense of smell. The smell of perfume is the result of molecules that rapidly evaporate from liquid and more through the air until they are close enough to our noses to be inhaled. They wander aimlessly around in
Compound
substance that is made up of atoms of different elements combined in a fixed position. Compounds have different properties from the element that they are made of. At ordinary temperatures, water is a liquid, whereas hydrogen and oxygen are both gases (bot
Chemical Formula
A description that uses numbers and symbols of elements to describe the proportions of elements in a compound reaction
Explain things that are and are not compounds
Water, table salt, carbon dioxide are all compounds. (h2o, get it? two hydrogens plus a oxygen). Air, wood, and salty water are not compounds because the proportions vary, doesn't have a chemical fomula set in stone
Is a compound made up of molecules?
A compound may or may not be made up of molecules
Atomic nuclei are extremely _____ and extremely ____
Atomic nuclei are extremely compact and extremely dense