Particles and Atoms Flashcards
(45 cards)
What sort of gases did the atmosphere contain around the time of the Big Bang?
carbon dioxide, water, nitrogen, methane, ammonia, hydrogen cyanide
Briefly explain how DNA was first formed (and what DNA stands for.
DNA (Deoxyribo Nucleic Acid), a very complex molecule, was formed when small molecules joined together over time.
Where is DNA found?
In all cell nuclei
What is the photosynthesis equation?
6H2O + 6CO2 - C6H12O6 + 6O2
Talk a little about carbon dioxide.
Carbon dioxide undergoes sublimation (straight from solid to gas and vice versa). Solid CO2 is called dry ice. It is used in fire extinguishers.
Talk a little about nitrogen.
It is an unreactive gas which can be converted into ammonia which is used to make fertilisers.
Talk a little about oxygen.
A gas that will combust (burn) a fuel.
Talk a little about phosphorus.
It burns with a bright flame in oxygen, making phosphorus oxide which is used to make fertilisers.
Talk a little about sulphur.
It burns with a blue flame in oxygen, forming sulphuric dioxide which is used to make sulphuric acid (H2SO4) which is used in car batteries and is also one of the gases that causes acid rain.
What is an element?
An element is a substance made up of only one kind of atom.
So far, how many element do chemists know of?
about 105 elements (about 90 of which are found in the Earth and atmosphere naturally and about 30 of which have been artificially made in a lab)
What categories do the left, middle and right of the periodic table represent?
On the left side, there are the metals. In the middle, we find the semi-metals. And on the right, there are the non-metals.
What simple test can one carry out to determine which group (metal or non-metal) and element belongs to?
You have an electric circuit with a bulb and two clips. If the element attached to the two clips is a metal, the bulb lights up. If the element is a non-metal, it doesn’t light up. (Metals conducts electricity)
What is the most common element in the Earth’s crust and in the human body?
Oxygen
What is the most common metal in the Earth’s crust?
Aluminium
What is the most common metal in the human body?
Sodium
What are atoms?
Atoms are the smallest particles of matter, that we cannot break down further by chemical means.
What is the difference between a mixture and a compound?
A mixtures is made from different substances that are not chemically joined whereas a compound is made of atoms of different elements, bonded together.
What does the name of a compound with 2 elements end in?
-ide
What does the name of a compound with oxygen end in?
-ate
How many atoms are needed, joined end to end, to measure 1cm?
one hundred million atoms
Which element has the smallest atoms? What is the mass of each atom of this element?
Hydrogen atoms have a mass of about 1.7 * 10^-24 g
What charge does a proton have and what is its approximate mass in amu?
A proton has a charge of +1 and a mass (amu) of about 1
What charge does an electron have and what is its approximate mass in amu?
An electron has a charge of -1 and a mass (amu) of about 1/1800th of a proton/neutron