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Flashcards in 1 - Water And Carbon Deck (30)
0

What are the most abundant elements on earth?

Carbon
Hydrogen
Nitrogen
Oxygen

1

Rank the following chemicals (most negative to least) based on their electro-negaitivity
Carbon
Nitrogen
Oxygen
Hydrogen

Oxygen
Nitrogen
Carbon = hydrogen

2

Describe a covalent bond

A type of chemical bond where electrons are shared

3

Why do atoms make bonds?

To achieve stability
A desire to have their outermost shell full; therefore stable

4

Describe the valance electron

The electrons which react = in the outermost shell and are unpaired

5

What are the different types of bonds?

Covalent bonds
Non-polar bonds
Ionic bonds
Polar covalent bonds
Hydrogen bonds

6

Explain electro negativity

Some molecules hold electrons more tightly than others. One side of a molecule will be charged positive and the other side more negative like H2O

7

Describe a non-polar covalent bond

The electrons are shared =
Symmetrical
H-H

8

Describe covalent bond

Electrons are shared

9

Describe what is going on with the electrons in a polar covalent bond

Electrons are not shared equally
Asymmetrical sharing
Change of charge on either side of the molecule

10

Describe an ionic bond

Where electrons are transferred from one atom to another -> stable outermost shell
Has protons so each atom has a charge cause by balance between protons and electrons
NaCl

11

Describe hydrogen bond

Occurs when the positive H which is part of a polar covalent bond is attracted to another charged negative atom in another polar bond
Takes energy to break that bond to change it's structure

12

What are the six properties of water?

cohesion
adhesion
surface tension
less dense when in solid form
high capacity for absorbing energy
solvent

13

describe cohesion

binding between molecules - helps them stay together

14

describe adhesion

binding of unlike molecules
ie glass and water

15

describe solvent

ions and polar molecules become surrounded by H2O molecules -> dissolve due to partial charges
and agent for getting substances into a solution

16

describe surface tension

more ordered @ air - H2O interface
resistance from H2O to depress water surface
has an elastic membrane

17

Describe what's going on with H2O and energy

it takes lots of energy to heat water because the first step is to break the H bonds

18

Is H2O more or less dense when comparing it in a liquid form to a solid

It is more dense as a solid therefore it floats
the molecules forms a crystal lattice because of the H bonds with the H2O molecules

19

How does Magnesium act as a laxative?

Mg+2 attracts the H2O molecules because of it's polarity, the water is drawn from the surrounding tissue therefore moistening the stool and helping elimination

20

Which molecule is in the shape of a V

H2O

21

Name the four types of bonds in range of strongest to least

Non-polar covalent bond
Polar covalent bond
ionic
hydrogen

22

Name which type of bond best describes the following:
It occurs with the positive Hydrogen which is part of a polar covalent bond, when attracted to another charged negative atom in another polar bond

hydrogen bond

23

Describe what happens to the water molecules as NaCl disolves into h20

the H2O lines up so that the electronegative side of the molecule lines up with the Na - O
and conversely with the Cl where the H lines up around it

24

What does a base do?

accepts H bonds
Lowers the pH concentration

25

What does an acid do?

an acid is a proton donor, it raises the hydrogen ion concentration in H2O & raises the proton concentration

26

Carbon is a very important substance for life on earth, it is the most _________ substance on earth

versatile

27

What atom enables large complex molecules to exist?

Carbon - it has 4 free places in its valance shell there for is very adaptable

28

function follows _______

form

29

List out the 5 carbon groups
the functional groups that make things happen

Amino & carboxyl
carbonyl
Hydroxyl
Phosphate
sulphryl