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Chemical Bonding.

Atoms of different elements join together to form compounds.

E.g: Na (Sodium) + Cl (Chlorine) + NaCl (Sodium Chloride).

When this happens, a chemical reaction has taken place, and the atoms are chemically bonded.

Octet Rule: Atoms bond together so that each atom attains an electron arrangement with a complete outer shell.
-Elements with a complete outer shell are very stable.

Not all atoms can chemically combine. If they don't combine with the octet rule, they will not react together to form a compound.

1) Ionic Bonding: (Giving and Taking)
One atom giving away its outermost electrons, and the other taking them, so they both end up with complete outer shells.

2) Covalent Bonding: (Sharing)
Both atoms sharing their outermost electrons so that they both end up with complete outer shells.

Covalent Bonding.

Atoms sharing electrons so they both have complete outer shell.

1) Hydrogen + Hydrogen = Hydrogen Molecule (H2)

2) Hydrogen + Hydrogen + Oxygen = Water Molecule (H2O)

3) Hydrogen + Hydrogen + Hydrogen + Hydrogen + Carbon = Methane Molecule (CH4)

A double covalent bond is formed when atoms share two pairs of electrons.

4) Oxygen + Oxygen = Oxygen Molecule (O2)

Light.

Light is a form of energy. (Crooke's Radiometer)

Light travels in straight lines.
-A shadow is total or partial darkness behind an object blocking light.

Reflection is when light bounces back or reflects off a surface.
-In a periscope, light is turned through 180 degrees.

Refraction is the bending of light as it passes from one medium to another.
-The light rays get pulled towards the denser substance.

A lens is a piece of glass with a curved surface which refracts light passing through them.

1) Convex/Converging Lens: Bends light rays together. Corrects long-sighted vision.
2) Concave/Diverging Lens: Spreads light rays out. Corrects short-sighted vision.

White light is a mixture of seven colours - red, orange, yellow, green, blue, indigo, and violet.
-Spectrum of white light.

Dispersion is the breaking of white light into its colours.

The time had finally arrived. It was the day we had all been waiting for. It was the day of the Under Fifteen National Cup Final. I play in goal for Lakewood Athletic and we were playing Cherry Orchard, last year’s winners and the best team in Ireland, in the final. The match was taking place in Croke Park, one of the biggest stadiums in the world with a capacity of over 80,000.

Only a few weeks earlier, I wasn’t playing football at all. I had always wanted to join Lakewood Athletic, my local team, but I never had the self-belief and courage to register with them. I used to spend countless hours watching them train and watching their matches. Two weeks ago, my luck changed. It was a cold Thursday night and I was out watching the team train, when the Lakewood goalkeeper landed awkwardly on his arm, breaking his humerus. As I was the only other person around, the Lakewood manager asked me to play in goal for the rest of the session. I gladly agreed, and I performed so well that I was asked to join the team permanently. I was delighted, and look where I was now…

The match was on a Saturday afternoon and we departed Cork early Friday morning. We travelled up to Dublin in a luxury bus, followed by bus-loads of enthusiastic supporters. Upon arrival, we checked into the five-star Carlton hotel, before travelling to Croke Park where we held a light training session on the pitch. We then headed back to our hotel and settled down for the night. It was a bit boring as we weren’t allowed to do anything and we were on a strict diet. I was starting to feel very nervous, but I could feel the excitement building inside of me. The match could not come soon enough…

The morning of the match, we were called at eight o’ clock. We were only allowed to have scrambled egg and toast for breakfast and we were made drink plenty of water. Just before we left the hotel, we held a brief team meeting where we discussed how we would approach the match. Shortly after, we got on our bus and headed for Croke Park. The match was getting ever closer and I was starting to feel the pressure…

We arrived at Croke Park two hours before kick-off and already the supporters had started shuffling in. We walked out onto the pitch to see what condition it was in, and it was the best pitch I had ever seen. We went into the dressing room where we talked about our tactics, got our gear on, and founded out the staring eleven. As I had expected, I was starting in goal. We headed back out onto the pitch where we warmed up briskly in-front of our supporters. We then returned to the tunnel, where we walked out onto the pitch with Cherry Orchard and stood for the national anthem. By now the stadium was full and the crowd were ecstatic. I had butterflies in my stomach but I was raring to go…

The referee blew his whistle and the game began. We started well, but we could not breakdown the Cherry Orchard defense. The game then started to even out and neither side could engineer any clear-cut chances. The game continued without event until the referee brought a stop to the action for half-time. Our manager tried to motivate us in the dressing room, but it was a tough, tight game. We went back out for the second half, eager to find a goal. We started on the front-foot and we managed to manufacture a couple of half-chances but we could not beat the Cherry Orchard ‘keeper who was in fine form. With only minutes to go, the game was stills scoreless. We searched desperately for a winner, but we just could not score. The referee blew his whistle for full-time, bring the game to the dreaded penalty shootout.

We had practised penalties for an hour at the training the day before the match, so we were cautiously confident heading into the shootout. You could feel the tension growing around the stadium as the shootout progressed. After both teams had taken four penalties, the score was tied at four-four. Our striker stepped up to take our fifth penalty and he confidently slotted the ball into the top left-hand corner. We had the advantage. All the pressure was on them and they had to convert their last penalty. Their central midfielder, who had controlled the game in midfield, stepped up to take the penalty. I had a feeling I was going to save the penalty. As he was waiting for the referee’s whistle, I tried my best to put him off. He ran up and smashed the ball low to my right-hand side. I had guessed the right way, and somehow I was able to get my outstretched palm to the ball and push it away. The crowd went into raptures. Everyone was going crazy and began running towards me. It took awhile to sink in but we had won the National Cup and I was the hero! Thinking of where I was a few weeks before, I was very lucky to be there. I was at the right place at the right time.

Soil.

Soil is a thin layer of loose material on the Earth’s surface. It is the substance in which plants grow; therefore, without soil, we would not survive. Soil is an important natural resource.

Soil consists of a mixture of five main ingredients.
1) Mineral Matter: Biggest ingredient. Remains of rocks that have been broken down into small particles such as silt, clay, and sand.
2) Air: Fills the spaces between the soil particles. Contains oxygen and nitrogen, which are required for the growth or roots and the survival or organisms in the soil. Also helps with the formation of humus.
3) Water: Contains dissolved minerals (nutrients) which plants can absorb through their roots, aiding plant growth.
4) Living Organisms: Creatures such as earthworms, slugs, and insects. Also home to millions of micro-organisms such as bacteria and fungi. Help to break down dead plants to form humus, increasing soil fertility.
5) Humus: Dark, partly decayed organic material formed from the remains dead creatures and plant litter. These are broken down and mixed with the soil by living organisms. Humus provides nutrients to enrich the soil.

Weathering: Breakdown of rock by chemical and mechanical weathering.
Leaching: Heavy rainfall washes nutrients, minerals, and humus downwards into the subsoil. Infertile soil. Some of the leached material builds up in the subsoil and hardens, forming an impermeable hardpan – poor drainage, boggy conditions.
Humification: Plant litter and dead creatures in the topsoil are mixed into the soil by living organisms, forming humus. Dark, retains moisture, provides nutrients, ties soil together.

Soil profile: A vertical section through the soil – three different layers - A Horizon, B Horizon, and C Horizon.
• A Horizon: Topsoil. Dark in colour, high humus content. Rich in organisms.
• B Horizon: Subsoil. Lighter in colour, less humus. More stones than the A Horizon (closer to earth’s crust, and protected from weathering).
• C Horizon: Lowest layer. Consists of solid bedrock. Original material that soil was formed from.

Brown Soils:
• Ireland’s most common soil.
• Formed under deciduous trees.
• Rich supply of leaf litter, broken down into fertile humus.
• Brown colour – high humus content.
• Fertile topsoil.
• Low levels of rainfall result in low levels of leaching – no loss of nutrients from the topsoil. Well drained.

Podzol Soils:
• Common in Irish uplands.
• Formed under coniferous tress, needle-shaped leaves.
• Poor supply of leaf litter, limited build up humus in the topsoil.
• Heavy rainfall leaches out minerals and nutrients.
• Ash-grey colour.
• Hardpan builds up in subsoil.
• Infertile soil, poorly drained, boggy.

Tropical Red Soils:
• Occurs in tropical regions.
• Develops in hot and wet conditions – equatorial climate.
• High rainfall and high temperatures quickly weather rock.
• Deciduous trees produce massive supply of leaf litter.
• Rapid breakdown into humus, and nutrients for the trees.
• High rainfall leaches out nutrients and minerals.
• Iron oxidises, rusting – red in colour.

Expenditure.

Expenditure is money we spend.
Fixed expenditure is money we spend at regular periods and can be anticipated. (Mortgage)
Irregular expenditure is money we spend that cannot be anticipated. (ESB Bill)
Discretionary expenditure is when you spend your money on entirely optional things. (Holiday)

Planning for future spending is called budgeting.

Impulse buying is buying on the spur of the moment, without planning. Impulse buying can lead to buying something you do not need, and you won’t have money left over for essential expenditure.

The opportunity cost is the item you have to do without, if you purchase another item.

Worked Example:
Conor has €1 going into the shop. He sees a can of coke for €1 and a Moro for €1. He would like both, but he can only afford one.

Conor decided to buy the can of coke, so the opportunity cost of the can of coke was the Moro.

A false economy is when you think you are getting a good deal, but you are actually not. (Buying a pair of Dunnes runners for €10 that may last six months, rather than buying a pair of Nike runners for €50 that will last four years)

Current Expenditure is buying goods and services that will be used in the short term.
Capital Expenditure is buying goods that are expected to last a few years.

An Aimsir Láithreach & Gnáthláithreach

Irish Seanfhocail's

rainaa wrote: »

i haven't gone through the thread, but i have history notes for all 3 years i made myself i can post if no one has posted them already?

Ya that'd be great, thanks!

hi guys,
these are some notes from thephysicsteacher.ie, i find them very helpful

Biology:

http://thephysicsteacher.ie/juniorcertbiologyhome.html


Chemistry:

http://thephysicsteacher.ie/juniorcertchemistryhome.html


Physics:

http://thephysicsteacher.ie/juniorcertphysicshome.html