Kemi - VT:23

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Ions

when atoms gain or lose electrons

Valency

The number of electrons the atom needs to gain or lose to become "full".

ionic compound/bonds

when a metal reacts with a nonmetal. They bond by giving or receiving one or more electrons to fill their outer shell. Giving one a positive and one a negative charge therefore attracting each other.

What is a covalent bonf?

it is formed by two non-metals bonding together. The atoms will form a covalent bond, which means that the atoms will share electrons to make a full, stable outer shell.

Vad står prefixen "Mono" för?

1

Vad står prefixen "di" för?

2

Vad står prefixen "tri" för?

3

Vad står prefixen "tetra" för?

4

Vad står prefixen "penta" för?

5

(2) Hydrogen + (1) Oxygen

Dihydrogen monoxide

(1) Carbon + (1) Oxygen

carbon monoxide

P(2)O(5)

diphophorus pentaoxide

Enthalpy

The amount of heat used or released in a system in Jiule/kilogram

Chemical energy

Energy stored in chemical bonds

exothermic reaction

A reaction that releases energy in the form of heat/light/sound

Endothermic reaction

heat/light/sound energy converted to chemical energy

What do we need nitrogen in our bodies for?

To build Amino acids to build proteins/DNA/RNA

Why is it hard to get the nitrogen into our bodies?

Nitrogen appears naturally as a 3-bond covalently bonded molecule which is hard to seperate.

Name 2 ways nitrogen can be 'fixed' into the ground:

1: Nitrogen fixing bacterias. 2: Lightning strikes

Nitrogen fixation

Process of converting nitrogen gas into ammonia, which is absorbed by organisms.

Nitrification

The process in which bacteria in the soil use oxygen to change compounds of nitrogen on dead plant material into nitrates which plants can then absorb as food.

Assimilation

The process by which plants and animals take in the (Nitrate) NO3- and ammonia formed through nitrogen fixation and nitrification.

Denitrification

the microbial process of reducing nitrate and nitrite to gaseous forms of nitrogen, principally nitrous oxide (N2O) and nitrogen (N2).

Eroding of phosphate-rich rocks

Over time, rain and weathering cause rocks to release phosphate ions and other minerals.

Geological uplift

Nitrogen-filled sedimentary rock moves from the ocean floor onto land over a very long period of time through a process called geological uplift.

Phosphorus absorption by plants

Plant roots absorb phosphorus from the soil solution.

Break down of organic matter.

Organic nitrogen is converted to mineral nitrogen (mineralisation) during the breakdown of soil organic matter by soil organisms or through nitrogen fixation by legumes.

What are positive & negative ions

Positive ions have one or more protons more in the nucleus than electrons. Negative ions have one or more protons less in the nucleus than electrons

synthesis

The combination of one or more elements to form a new product or products.

Decomposition

A chemical reaction that breaks down compounds into simpler products.

single-displacement reaction

a reaction in which one element takes the place of another element in a compound

double-displacement reaction

a reaction in which a gas, a solid precipitate, or a molecular compound forms from the apparent exchange of atoms or ions between two compounds

Exothermic

When a reactions is releasing energy

Endothermic

When a reactions is absorbing energy

reactants

A starting material in a chemical reaction

product

A substance produced in a chemical reaction

Atmospheric nitrogen

Is nitrogen found in the atmosphere in the gas form. N2 forms about 78 % of the earths atmosphere.

Bactrias

*Bacteria* are microbes with a cell structure simpler than that of many other organisms.

ammonium

Ammonium is a positive ion of ammonia.

Decomposer

Are organisms that break down dead or decaying organisms.