C2 Elements, Compounds And Mixtures Flashcards
How are molecules formed?
Molecules are doomed when atoms bond together. Molecules can be made of the same element and different elements.
How big is a nanoparticle?
They are typically made of around 100 atoms and range from 1nm to 100nm in size.
What is the mass number and where is it on the periodic table?
The mass number is the total number of protons and neutrons and it is found under the element’s symbol (it is usually the larger number).
What is the atomic number and where is it on the periodic table?
The atomic number is the number of protons and it is found above the element’s symbol.
How can you find the number of neutrons?
You can find the number of neutrons by subtracting the atomic number from the mass number .
Why do neutral atoms have no charge overall?
Neutral atoms have no charge overall because they have the same number of protons and electrons. The number of electrons in a neutral atom is also equal to it’s atomic number.
How are ions formed?
Ions are formed when atoms (or groups of atoms) gain or lose electrons.
When are negative ions formed?
Negative ions are formed when atoms gain electrons and they have more electrons than protons.
When are positive ions formed?
Positive ions are formed when atoms lose electrons and they have more protons than electrons.
What are isotopes?
Isotopes are different forms of the same element, which have the same number of protons but a different number of neutrons.
How many protons, neutrons and electrons does carbon-12 have?
Protons=6
Neutrons=6
Electrons-6
How many protons, neutrons and electrons does carbon-13 have?
Protons=6
Neutrons=7
Electrons=6
Describe in terms of forces and energy need to break bonds is determined by the size of the molecule.
Smaller molecules have weaker intermolecular forces between them meaning that less energy is needed to break their bonds in order to form a gas. Larger molecules have stronger intermolecular forces since the size of the force increases as the size of the molecule increases; this means that more energy is needed to break their bonds.
What is nanotechnology?
The use and control of structures that vary on a nanoscale- 1-100 nanometers (1 millionth of a millimeter). These occur naturally in sea spray, for example, but most nanoparticles are created by scientists for nanotechnology purposes. It can also be created by accident for example as the smallest particulates from combustion of fuels.
How is nanotechnology used?
Nanoparticles can modify the properties of polymers. For example, some are used in clothes for antibacterial purposes (which prevents bad smells), and some are used in certain sports equipment (tennis rackets, golf clubs etc.) to make them lighter but stronger.
What do nanoparticles show in comparison to larger particles?
Different properties this is because they have a much larger surface area of the nanoparticles compared to their volume.
What are the dangers of Nanoparticles?
The way they affect the body isn’t fully understood, new products need to be tested thoroughly to minimize the risks.
The long-term impacts are not fully known. Many people want products containing nano technology to be clearly labeled.
Some are worried that products containing nanoparticles have been made available before the effects on human health have been properly investigated. We don’t know the long term imapacts.
Relative Atomic Mass
Bigger number on Periodic Table (Top).
Relative Formula Mass
Relative Atomic Masses added together in a compound.
Mass Conservation
Idea of atoms are never destroyed nor made, rather changed. Same mass.
Atom Economy
% of Reactants changed to Useful Products.
Waste Product
Product which isn’t needed
Chromatography
The extraction of a substance or chemical from a compound.
Pure Substances
Can’t be seperated by Chromatography. Specific melting and boiling point.
Inpure Substances
Can be seperated by Chromatography. Has a low melting point and a high boiling point.
Allotropes
Different structural forms of the same element in the same physical state.
Diamonds
Lustrous, Colourless and very hard Due to strong Covalent Bonds. Doesn’t conduct electricity due to lack of free ions or electrons.
Lustrous
Sparkly.
Strong Covalent Bonds
High Boiling Point, Hard to break, good cutting tools.
Weak Covalent Bonds
Low Boiling Point, Easy to break, not very good cutting tools.
Graphite
Black, Opaque, Shiny, 3 Covalent bonds that are layered, layers are very weakly held together. Good for Pencils and Lubrication. High melting point. Only 3 of 4 electrons are used in bonding, so lot of delocalised electrons are present, conducting electricity.
Giant Molecular Structure
Diamond and Graphite are examples of this.
Fullerenes
Molecules of Carbon, shaped like closed tubes, or hollow balls. Can cage other molecules.
Fullerenes could lead to…
Slow release drugs.