Chemistry 1 - Core Flashcards
What is the Earth surrounded by a thin layer of?
Atmosphere
What does the atmosphere contain?
78% nitrogen 21% oxygen 1% argon (other noble gasses) Small amounts - water vapour, carbon dioxide and particulates) CO2 - 0.035%
When was the Earth formed?
4.6 billion years ago
What did the earliest atmosphere contain?
Ammonia, water vapour, carbon dioxide
How did the seas form?
From water vapour in the atmosphere
What lead to the decrease in atmospheric carbon dioxide, and increase in oxygen?
The evolution of photosynthesising organisms
What happened to carbon dioxide after it dissolved in the oceans?
Carbon became locked up in sedimentary rocks as carbonates and fossil fuels
What are pollutants?
Chemicals that harm the environment and our health
What can pollutants affect directly?
Food chains, health etc
How can pollutants have an indirect effect?
Through acid rain etc - it causes things which in turn have an effect
What is carbon dioxide harmful to and how?
The environment - traps heat in the earths atmosphere - leading to global warming
What is nitrogen oxide harmful to and how?
The environment and humans - can cause acid rain and breathing problems and make asthma worse
What is sulfur dioxide harmful to and how?
The environment and causes acid rain
What is carbon monoxide harmful to and how?
Humans - displaces oxygen in blood - binds to oxygen cite on red blood cell permanently
What are particulates harmful to and how?
Environment, humans, make buildings dirty - make asthma and lung infections worse if inhaled
How is pollutant concentration measured?
In Parts Per Million (ppm) and Parts Per Billion (ppb)
What can affect the measuring of pollutants?
1- variables (volume of traffic and weather)
2- measuring equipments accuracy
3- use of skill (will effect the use of accuracy and precision)
What are outliers?
They do not follow the general pattern of data - normally indicate some form of error
Why is it important to repeat measurements?
A single set of data may not be reliable - you cannot tell
How can you overcome small variations and get an estimate of the true value?
By calculating the mean
Where do the carbon monoxide emissions come from?
Around half from road transport, the rest from homes and other idustries
What is the correlation between carbon monoxide in the city and in the country park?
The mean carbon monoxide in the city is significantly higher than the park, supporting the theory it is produced by humans
What are elements?
The building blocks for all materials
How many elements are there?
Over 100
What are elements made up of?
Very tiny particles called atoms
What is specific about the atoms in one element?
They are all the same, and are unique to that element