Gabrielle

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**6th Oct, 2010**

Robert Boyle (25 January 1627 – 31 December 1691) was in Irish philosopher, chemist, physicist and inventor who is best known for Boyle's Law.

Jöns Jacob Berzelius, (20 August 1779 – 7 August 1848) was a Swedish chemist. He developed a table of atomic weights and introduced letters to symbolize elements. He worked out the modern technique for modern formula notation along with others and is considered one of the fathers of modern chemi stry.

. Dmitri Ivanovich Mendeleev (8 February1834 – 2 February 1907)also developed a table of elements, separate to Meyer. He was a Russian chemist and inventor, and also predicted the properties of elements yet to be discovered using his table. Though they both play a major role in the creation of todays periodic table, Mendeleev is usually the one credited with its invention.


 * Contribution to the development of the periodic table or the atomic theory ||
 * Greek thinkers || The ancient Greeks were the first to think that all matter was made up of tiny individual particles. They used the terms "atom" and "element" ||
 * Lavoisier || Atoine Lavoiser. (26 August 1743 – 8 May 1794) Born in Paris, France. He wrote the first extensive list of elements, contaning 33. He distinguished between metals and non metals, stated the first law of conservation of mass and helped to construct the metric system. He discovered that, although matter may change its form or shape, its mass always remains the same. He also discovered oxygen in 1778 and the significance of it in combustion. ||
 * John Dalton || (6 September 1766 – 27 July 1844) He was a chemist, meteorologist and physicist from England. In the year 1803, he proposed the atomic theory. This was that all matter was made up of tiny individual particles called atoms, and that atoms of different elements possessed different characteristics. He also believed that there were 3 kinds of atoms. Simple atoms (elements), compound atoms (simple molecules) and complex atoms (Complex molecules) . This was presented in 1808 to 1827. ||
 * Doberiner || (December 13, 1780 – March 24, 1849) His work prefixed the periodic law and the laws of elements. ||
 * De Chancourtois || (July 13, 1826 – May 10, 1910). Using these elemantal weights developed by Cannizzaro, Alexandre-Emile Beguyer de Chancourtois created a fully functioning periodic system on a cylinder. He called it the Vis Tellurique. It allowed all the known atoms to be placed in an unbroken order of the increasing weight of their atoms. ||
 * Cannizaro || Satanislao Cannizzaro was an Italian chemist who determined the atomic weights for elements known in the 1860's. He is mostly remembered for the Cannizarro reaction today. ||
 * Newlands || (1838-1898) He was an Englishman who became a chemist in 1864 John Newlands was the first person to come up with a table of elements arranged in order of their atomic weights. In 1865 he published his “law of octaves” which states that “any given element will exhibit analogues behaviour to the eighth element following it in the table" ||
 * Meyer || (August 19, 1830 - April 11, 1895) He was a German chemist, who in 1869, put together a periodic table of 56 different elements bast on things like molar volume when arranged in order of their atomic weight. ||
 * . Mendeleev || He was a chemist and inventor from Russia. Though not the only one responsible, he gets most of the credit for creating the first version of the periodic table. He lived from 8th February 1834 to the 2nd of February 1907. 1869 was when he published his work, but he aslo saw the gaps in his table, and predicted the properties of missing elements. He earned respect from his peers when his predictions began to come true. ||
 * Moseley ||  ||
 * Seaborg || Seaborg was a Swedish man who lived from April 19, 1912 to February 25, 1999. He won the nobel prize for chemistry in 1951 for discoveries in the chemistry of the transuranium. He also contributed to the discovery and isolation of 10 elements and developed the //actinide concept.// This let to the modern arrangement of the actinoid series in the table of elements. ||
 * Democritus || He was an ancient greek philosopher who lived from 460 B.C 370 B.C. He was an influential pre-Socratic philosopher and pupil of Leucippus, who put together an atomic theory for the cosmos. Most of his work exist now only in second hand reports, which can be unreliable or conflicting. The best evidence of what work he did was reported by Aristotle, who wrote a monograph on him. ||
 * Rutherford ||  ||
 * JJ Thompson ||  ||
 * Bohr ||  ||
 * Schrodinger ||  ||
 * Heisenberg ||  ||

(July 13, 1826 – May 10, 1910). Using these elemantal weights developed by Cannizzaro, Alexandre-Emile Beguyer de Chancourtois created a fully functioning periodic system on a cylinder. He called it the Vis Tellurique. It allowed all the known atoms to be placed in an unbroken order of the increasing weight of their atoms. 20 January 1820 – 14 November 1886

Mendeleev also published his periodic table & law in 1869, but he also forecast the properties of missing elements, and chemists began to appreciate it when, soon after, the discovery of elements predicted by gaps in his table took place

1. a) Condensation is when gas becomes liquid  b) Sublimation is when solids turn to gas c) Melting is when solids become liquid

2.Freezing is when liquids turn solid and melting is when solids turn liquid.

3. If you heat the mixture up, the iodine in the mixture would sublime into gas, leaving only the sand, thus separating the two.

4. Osmosis is the movement of liquid molecules through a semi-permeable membrane, so that both sides of the membrane have the same concentration.

5. Brownian motion is the effect of motion small particles have on bigger particles.

1.A 2.C  3.D  4. C  5.B

6. Diffusion is the spread of particles through random motion.



b) Though the room is sealed and no air circulation is happening, the perfume particles would still diffuse and spread out around the room. A person sitting in the opposite end of the room to which the can was sprayed, would still be able to smell it.

c)

7. a)  i. Melting  ii. Freezing  iii. Evaporation  iv. Condensation  v. Sublimation

b) i. The particles are heating up and spreading out.  ii. The particles cool down and are compacted together  iii. The particles heat up and diffuse  iv. Gas particles become liquid  v. Solid particles turn straight to gas particles.

8. a) See question 4.  b)

Two liquids are separated by a semi-permeable membrane the bigger molecules are barred from getting through, while the smaller molecules can pass.

9. a)


 * Name || Formula || Mass || Order of diffusion ||
 * Ammonia || NH3 || 17 || 2nd ||
 * Carbon Dioxide || CO2 || 44 || 3rd ||
 * Hydrogen || H2 || 2 || 1st ||
 * Hydrogen || H2 || 2 || 1st ||

c) As hydrogen is the lightest gas, it would diffuse and spread out the fastest, ammonia would diffuse second and carbon dioxide third as it is the heaviest.

1. The three particles we find in atoms are, protons, neutrons and electrons.

2. The atomic number is the number of protons in the atom.

3. The mass number of an atom is the sum of the number of protons and the number of neutrons.

4. Carbon

5. Most of the time, there is no difference in the way icotopes behave. Differences occur when the icotpoes are unstable.

6. Carbon 14 is radioactive.

7. Radioactive icatopes keep food fresh longer by killing the microbes that start to grow in it.

8. Group 0 has 8 electrons in their outer shells.

9. . A carbon atom

10. Their lack of reactivity is associated with their electronic structures.

Chapter summary.

1. A 2. D  3. B  4. A  5. C

6. a) b) 11 c) 34 d) 6
 * || Mass || Charge ||
 * Protons || 1 || +1 ||
 * Neutrons || 1 || 0 ||
 * Electrons || 1 || -1 ||

7. a) 18  b)  i)  ii)

iii)

c) i and iii

8. a)
 * protons || neutrons || electrons ||
 * 6p || 6n || 6e ||
 * 6p || 8n || 6e ||

b) isotopes

c) Lithium 6 is an example of an icotope because it has an unusual number of neutrons.

9) Because isotopes have an unusual amount of neutrons, they alter the atomic mass of atoms.

b)

c)

10. a) They are the amount of electrons that can fit into each shell of an atom, from the innermost shell to the outermost shell.

b) This is not an ordinary atom because there is a difference in the number of protons and electrons.

c) i) 33a ii)+1 iii)

11) a) The radiation given off by radioisotopes can kill cancer cells. b) Invasive surgery is extremely risky and using radiation, while it has its drawbacks, may be a safer method of removing cancerous tumors. In some cases, radiation is better when surgery may be too risky.

c) Radiation in excessive amounts is dangerous, the rules exist to prevent unnecessary injury.

d) Carbon dating is the process in which scientists use the radiation from the atom carbon 14 to accurately trace and find the age of carbonaceous materials.It is useful because it reveals a lot about the history of different species and is important in theories like evolution.

12) a) 9 b) The mass number of an atom is the the sum of all its sub-atomic particles. c) There are 9 protons, 9 electrons and 1 neutron. d)

1)A fossil is any preserved evidence of organic life.

2) Relative dating is a method of roughly determining the age of a fossil by comparing several factors such as location and what layer of soil it was found in ect. This method however is not absolute and is therefore called relative dating.

3) Absolute dating is a method of determining the approximate age of an organic substance and is usually based on physical or chemical properties of the given substance.

4) The geological time scale is a system of chronological measurement that is used by scientists to, in a sense, map out earth's biological history.

5) Extinction is when an organism or a group of organisms, namely a species is completely eradicated and no longer exists.

6) Tectonic plates are part of a scientific theory of what makes up the earth's crust or lithosphere. Scientists believe that the earth's crust is made up of several distinct pieces called tectonic plates. Over time, these plates move or shift, splitting apart and taking countries with them, causing something scientists call continental drift. This process happens over a time period of millions of years and continues up to this day.

Section 2.

1) The Precambrian era is an era on the geological time scale from 4600 to 545 million years ago when macro-scopic hard shelled animals first began to appear in abundance. This era is divided up into several eons and existed before the current Phanerozoic eon.

2) The Paleozoic era was the first of the 3 geological areas within the Phanerozoic era, this was the time that the first species of primitive fish and plants began to appear. The era lasted roughly from 542 to 251 million years ago. By the end of it the first large reptiles and forests with modern plants had evolved.

3) The Mesozoic period lasted from about 250 to 65 million years ago and is known by some as the age of the dinosaurs as most dinosaurs developed and went extinct during that time, plants were also rapidly changing.

4) The current era, the Cenozoic era starts from 65 million years ago to the present day.