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Bio 1610 Pittilleri > Atoms-Molecules > Flashcards

Flashcards in Atoms-Molecules Deck (28):
1

Subatomic Particles

-Protons (+) Charge
-Neutrons no Charge
-Electrons (-) Charge

Reside within the Atomic Nucleus

2

Elements

They cannot be broken down or converted to other substances.
- they have an atomic # that is determined by the # of protons in the nucleus.
-there are 92

3

Isotopes

When atoms of the same element have different #'s of neutrons.
- they can be radioactive

4

Electron Shells

Orbits held by electrons around a nucleus.
- 1st shell holds 2 electrons
-subsequent shells can hold 8 electrons
-shells allow for interactions with other atoms.

5

Molecules

Two or more atoms chemically joined

6

Compounds

A molecule that contains at least two different elements

7

Where do interactions happen on atoms?

In the outermost shell
-if outer shell is full-no reaction-inert
-if outer shell is not full-will react-reactive

8

How do atoms gain stability?

By reacting with another atom
-lose an electron- empty shell
-gain electron-fill shell
-share electron-so both atoms have a full shell

9

Chemical Reactions

Are the basis of life.
-making or breaking of chemical bonds.

10

Types of Chemical bonds

-ionic
-covalent
-hydrogen
-van dee walls interaction

11

Ionic Bonds

Formed between ions
- the atoms lose or gain electrons to become more stable. Therefore become slightly positive or negative.
- the oppositely charged ions are attracted to one another forming ionic bonds.
-water easily breaks these bonds

12

Ions

An atom which has gained or lost an electron.
- imbalance between protons and electrons
- slightly (+) or (-) charge

13

Covalent Bonds

When two atoms share an electron to both become more stable.

14

Nonpolar Covalent Bonds

When electrons are shared equally between two atoms of similar electro negativity.

15

Polar Covalent Bonds

The unequal sharing of electrons between two differing electronegative atoms.

16

Hydrogen Bonds

(+) charge of hydrogen is attracted to the (-) charge of another molecule ( like oxygen)
- mostly found between water molecules.
- very weak bonds(individually)

17

Van der Waals Interactions

As electrons move they create +\- charged regions on a molecule.
When Atoms/molecules are close they interact at oppositely charged regions
- very weak

18

Free Radicals

Molecules with atoms that have one or more unpaired electrons in there outer shells.
- they are very reactive
-will take an electron forcibly from something else-cell membranes/ DNA
- the lost electron from the second molecule creates another free radical.

19

Antioxidants

React with free radicals and make them harmless.
- like vitamin E and C

20

Water

Essential to life
- a very good solvent
-interacts with or dissolves many substances
-polar

21

Solute

What is dissolved in the solvent.

22

Hydrophilic

Substances that interact with water.
- have an electrical charge
--ions and polar molecules

23

Hydrophobic

Substances that do not interact with water.
-no charge
-nonpolar molecules
-hydrophobic interactions

24

Acid

Substances that release H+ when dissolved in water.

25

Base

Substances that release OH- when dissolved

26

pH scale

Expresses the degree of acidity
- scale runs from 0-14
-pure water = 7 neutral
-increasing acidity 6.9-1.0
-more basic 7.1-14.0
--each unit is a tenfold change

27

Buffers

Compounds that maintain pH
-can accept or give off H+ or OH-
--like bicarbonate (HCO3-)

28

Atoms

The fundamental structural unit of matter or elements

They have equal numbers of electrons and protons