Unit 2 Chapter 1 (Basic Chemistry) Flashcards
Matter
Anything that occupies space and has mass
Three Physical States of Matter
Solid, Liquid, Gas
Element
Substance that can’t be broken down to other substances by normal chemical means.
- 118 elements
- 92 found in nature
Compound
Substance consisting of 2 or more elements combined in a fixed ratio
- Has different characteristics than its elements
How many elements are organisms components made of?
3 or 4 elements
Number of elements needed for humans?
25 elements
Number of elements needed for plants?
17 elements
The Big Six
Makes up 99% of matter in our bodies
Building blocks of proteins, carbohydrates, and lipids
Oxygen, Carbon, Hydrogen, Nitrogen
Most important element for DNA
Phosphorous
Elements important for bones & teeth
P & Ca
Elements important for nerve signalling & chemical reactions
K, S, Na, Cl, Mg
Element essential for organisms
Iron
Element only needed by certain species
Iodine
Subatomic Particles
A particle smaller than an atom.
- Ex. proton
Atom
Smallest unit of matter that retains the properties of an element.
- Every element has its own unique atom.
Atoms can be split into which subatomic particles?
Proton, Electron, Neutron
Proton
Single positive charge
Electron
Single negative charge
Neutron
Electrically neutral in charges. It has the same amount of protons and electrons
Nucleus
Central core of an atom
What do electrons do around a nucleus?
They form a cloud of negative charges around it
What are negative electrons attracted to?
Postive protons
Atomic Number
Number of protons in atom
Mass Number
Number of protons and neutrons in nucleus
Atomic Mass
Weight of an atom
Isotopes
Atoms that have the same number of protons & behaves the same way chemically with different number of neutrons.
- All atoms of an element have the same atomic number but different mass numbers.
Radioactive Isotope
It’s when the nucleus is unstable and decays, which releases particles & energy (radiation).
- Radiation damages cellular molecules
- Radioactive molecules are used to date fossils.
Unstable Isotope Example
C14
Stable Isotopes Example(s)
C12 and C13
How can radioactive isotopes be used in medicine?
- Can be used as a chemical tag to detect chemical buildup in certain areas of the body.
- Thyroid cancer can be targeted with radioactive iodine as iodine accumulates in thyroid.
Electron Shell Capacity
1st = 2 electrons
2nd = 8 electrons
3rd = 8 electrons
Chemical Activity of Atoms:
Only electrons are involved in chemical activity of atoms. Electrons can be found in different electron shells.
Valence Shell
- Outer shell of an atom
- Atoms interact to complete or fill valence shell
Valence electrons
Electrons on the valence shell
Inert Element
Element whos atom have a complete valence shell.
- They don’t interact with other atoms.
Chemical Reaction
Breaking chemical bonds & making new ones.
- Occurs when two atoms with incomplete shells come together.
Chemical Bond
Attraction & interactions between atoms
Ionic Bond
Transfer of electrons from an atom to another
- An atom strips an electron away from the other.
Covalent Bond
Sharing of electrons between atoms
Bonding Capacity (Valence)
The number of covalent bonds an atom can form
Molecule
2 or more atoms bound together by covalent bonds
Electronegativity
Atom’s measure of attraction for shared electrons
Non-polar Covalent Bonds
When electrons are shared equally since the 2 atoms have the same electronegativity
Polar Covalent Bonds
It’s when electrons are pulled closer to the more electronegative element
- One atom has a slightly negative charge while the other has a slightly positive charge.
- Oxygen is one of the most electronegative elements and has a high chance of creating a polar covalent bond.
Ion
An atom with electrical charge due to gain or loss of electrons.
An”ion”
Negative
Cat”ion”
Positive
Salt
Any ionic compound
- Are strong and hard when dry, but easily dissolvable in water.
- Many drugs are made of salt
Hydrogen Bond
Weak bonds within and between polar molecules
- Involves the atom of hydrogen
- Hydrogen is attracted to oxygen & nitrogen
Reactants in a chemical reaction
Starting materials
Balancing of Chemical Equation
Same amount of atoms on both sides of the equation
Products in a chemical reaction
Materials that result from chemical reaction
