Science fusion notes

An acid increases the number of positively charged H3O* ions when it dissolves in water. A base increases the number of negatively charged OH- ions when it dissolves in water.

The strength of an acid or base depends on the percentage of its particles that break apart to form ions in a solution. The strength of an acid or base is not the same as its concentration.

strong acids and bases break apart completely

weak acids and bases partially stay intact

Examples of physical changes -

Stretching a rubber band

Dissolving sugar in water

Cutting your hair

Melting butter

Bending a paper clip

Water Cycle

Crushing an aluminium can

Examples of chemical change-

Burning a candle

Boiling potatoes

Photosynthesis

Digestion

Rock Cycle

Physical properties of acids -

They taste sour

They conduct an electric current

Chemical properties of acids -

Acids are corrosive - they can react with and destroy body tissue, clothing, and many other things

Physical Properties of bases -

They taste bitter

Bases feel slippery

They conduct an electric current

Chemical properties -

They are caustic - They can burn or corrode other substances

A neutralization reaction is the reaction between an acid and base in a water solution

A salt is an ionic compound that forms from the negative ion and the positive ion of the base

examples of salts -

Sodium Chloride (NaCl) - baking soda, flavour food

Calcium Chloride ( Ca(OH)2 - keep ice from forming on roads and sidealks in winter

Sodium Nitrate - salt that preserves food

Calcium sulfate - plasterboard, an imp part of construction of buildings, chalk

The ph of a solution is a measure of how acidic or basic a solution is.

The pH of soil in any environment is important. If soil pH is too acidic or too basic, the nutrients that plants need do not dissolve into the water in the soil. When plants do not get the nutrients they need, they do not grow well. When plants cannot thrive, the population of animals that depends on the plants as a food source also suffers, and an entire food web may collapse.

In most ocean environments, the water has a pH of about 8. If too much carbon dioxide is absorbed by the water, the ocean pH may be slightly lowered. This lower pH could harm sea animals such as mollusks by causing their hard outer shells to dissolve. Other sea creatures that depend on mollusks as a food source would also suffer.

When sulfur oxides and nitrogen oxides are combiened w water they produce sulfuric and nitric acid. these acids form acid rain when they dissolve in precipitation as raindrops

Acid rain can lower the pH of lakes, ponds, and streams which decreases the pH. It can harm aquatic species, as well as other organisms that rely on the water for survival. Acid rain can harm plants by damaging their leaves and harm plants and other living things by lowering soil pH. Acid rain can damage buildings and sculptures made of limestone and marble. Acid rain reacts with the stone that makes up these structures and causes the structures to erode. Acid rain can also damage paint and cause metals to corrode faster.

The lungs remove carbon dioxide. If a person's kidneys or lungs do not work properly, blood CO2 levels can increase, lowering blood pH. The person develops acidosis. Alkalosis is usually caused by an increased breathing rate. The person's blood CO levels decrease, raising their blood pH.

Signs of Chemical Change-

Production of Odor

Production of Gas

Change in energy

Change in colour

The law of conservation of mass states that in ordinary chemical and physical change mass is not created or destroyed but only transformed into different substances

A physical change is a change of matter from one form to another without a change in the identity of the substance.

A chemical change is a change of matter that occurs when one or more substances change into new substances with different properties.

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