Chemistry
It is the most common element in the human body... A: Carbon, B: Hydrogen, C: Oxygen, D: Calcium
What is C. Oxygen. It makes up almost 63% of the average human. Following, are major elements and the percentages of the human body that they represent: Oxygen- 62.81% Carbon- 19.37% Hydrogen- 9.31% Nitrogen- 5.14% Sulfur- 0.64% Phosphorus- 0.63% Other- 2.10%
An atom that has lost or gained electrons in order to become charged
What is an ion?
This type of matter has a definite volume but no definite shape... A: Solids, B: Liquids, C: Gases, D: Plasma
What is B: Liquids. Liquids have a definite volume but no definite shape. Because the intermolecular forces are weak in a liquid, it is able to change its shape to conform to its container.
A bond that occurs between two non-metallic elements that share atleast one pair of electrons
Covalent bond
A given element that has the same number of protons but a different number of neutrons
What is an isotope?
These substances increase the rate of chemical reactions... A: Reactants, B: Catalysts, C: Isotopes, D: Cathodes
What is B: Catalysts. Catalysts are substances that increase the rate of chemical reactions by reducing the amount of activation energy
A process where ionic substances are decomposed into simpler substances when an electric current is passed through them
Electrolysis
How has an atom of magnesium become Mg2+?
Magnesium has lost 2 electrons
An allotrope of carbon that is arranged in layers and able to conduct electricity
Graphite
The protection of iron or steel against corrosion by using a more reactive metal
Sacrificial protection
The reaction between ethene and steam will make alcohol. The forward reaction is exothermic, what will happen if the temperature is increased?
Increasing the temperature will cause the reverse reaction to be favoured because it is endothermic.
Endothermic reactions take in energy from the surroundings.
Equilibrium would shift to the left.
A reaction occurs between Beryllium and chlorine, what is the molecular formula of the chemical compound that is formed?
BeCl2
Beryllium forms 2+ ions, chlorine forms - ions. A Compound must be neutral overall, therefore 2 chloride ions are needed to balance the 2+ charge.
Molten zinc bromide is electrolysed using graphite electrodes, what is the half equation of the reaction at the cathode?
A: Zn -> Zn2+ + 2e-
B: Zn2+ + 2e- -> Zn
C: Br- -> Br + e-
D: 2Br- -> Br2 + 2e-
B: B: Zn2+ + 2e- -> Zn
Zinc ions are found in the molten solution and are positively charged, therefore will deposit on the negative cathode as solid zinc
An aqueous solution of sodium chloride is electrolysed which species will be attracted to the anode?
Cl- and OH- will be attracted to the positive anode because opposite charges attract one another
These are microscopic spheres of 60 atoms of pure carbon in a spherelike structure that resembles a geodesic dome... A: Hydrocarbons, B: Lipids, C: Crystals, D: Buckyballs
What is D: Buckyballs. "Buckyballs" are microscopic spheres of 60 atoms of pure carbon in a spherelike structure that resembles a geodosic dome. Also called fullerenes or buckminsterfullerenes, they were named after R. Buckminster Fuller who invented the geodosic dome. Buckyballs are of great interest to scientists because they contain a cavity large enough to hold other elements, even whole molecules. Once an element has been deposited into the cavity, it cannot emerge without being heated to high temperatures. This technology may someday be used to deliver medication to specific locations within the body.