Candidate Number Candidate Name ______________________________________________ INTERNATIONAL ENGLISH LANGUAGE TESTING SYSTEM Academic Reading PRACTICE TEST 1 hour Time 1 hour INSTRUCTIONS TO CANDIDATES Do not open this question paper until you are told to do so. Write your name and candidate number in the spaces at the top of this page. Read the instructions for each part of the paper carefully. Answer all the questions. Write your answers on the answer sheet. Use a pencil. You
Premium Limbic system Helium Circadian rhythm
six noble gases that occur naturally are Helium (He)‚ Neon (Ne)‚ Argon (Ar)‚ Krypton (Kr)‚ Xenon (Xe)‚ and the radioactive Radon (Rn). They are all odorless‚ colorless‚ and are unreactive chemically. Noble gases are found in the atmosphere‚ the risk of a human being exposed is by inhaling; if the gases are not contained and release there is a serious risk of suffocation when confined to a small area. The gases are used in lighting and photography; Helium‚ Neon‚ Argon‚ and Krypton are used in gas
Premium Oxygen Chemical element Helium
press at all. Helium – an inert‚ odourless‚ monatomic element known to lay people as the substance that makes balloons float and voices squeak when inhaled – could be gone from this planet within a generation. B) Helium itself is not rare; there is actually a plentiful supply of it in the cosmos. In fact‚ 24 per cent of our galaxy’s elemental mass consists of helium‚ which makes it the second most abundant element in our universe. Because of its lightness‚ however‚ most helium vanished from our
Premium Helium Hydrogen
obtained by fractional distillation of air. • They are often used aboard chemical tankers and product carriers (smaller vessels). • Helium‚ Neon‚ Argon‚ Krypton‚ Xenon‚ Radon and are inert gases. • Duplet (Helium) or Octet • Full valence shell • • • • Weak interatomic force Very low melting and boiling points. Monatomic gases under standard conditions Helium has several unique qualities when compared with other elements: – Boiling and melting points are lower than those of any other
Premium Helium
Cryogenics and the Future Cryogenics is a study that is of great importance to the human race and has been a major project for engineers for the last 100 years. Cryogenics‚ which is derived from the Greek word kryos meaning "Icy Cold‚" is the study of matter at low temperatures. However low is not even the right word for the temperatures involved in cryogenics‚ seeing as the highest temperature dealt with in cryogenics is 100 (C (-148 (F) and the lowest temperature used‚ is the unattainable
Premium Superconductivity Temperature Oxygen
Neon’s state of matter is a gas substance. This element is colorless‚ odorless and tasteless. It is nonmagnetic. Despite the fact that neon is colorless under low pressure it glows in a reddish orange if an electric current passes through it. After Helium‚ Neon is the second-lightest noble gas.
Premium Helium Chemical element Periodic table
increases to about 10000 c . The reaction is carried out in an argon atmosphere to prevent magnessium and sodium from reacting with oxygen in the air. 3.Another gas used instead of argon. any of the elements in group O of the periodic table including helium ‚neon‚krypton‚xenon‚and radon which are monoatomic and with limited excemptions chemically innert. 4.Why titanium is an expensive metal Titanium is very expensive because it is akward to extract from ore -for example rutile‚TiO2 .You cannot use carbon
Premium Carbon dioxide Carbon Helium
emits an alpha particle it is alpha decay‚ the alpha particle emitted contains two protons and two neutrons which is equivalent to a helium nucleus being released. Alpha decay occurs because there are too many protons‚ which causes excessive repulsion within the nucleus‚ and in an attempt to reduce the repulsion the helium nucleus will be emitted from the atom. The helium nucleus is constantly colliding with the walls of the nucleus and due to its mass and energy it will tunnel out of the nucleus.
Premium Neutron Proton Chemical element
D lines) at 589.0 and 589.6 nm -- any sample that contains sodium (such as table salt) can be easily recognized using this pair of lines. One of the most dramatic triumphs of astrophysical spectroscopy during the 19th century was the discovery of helium. An emission line at 587.6 nm was first observed in the solar corona during the eclipse of August 18‚ 1868‚ although the precise wavelength was difficult to establish at the time (due to the short observation using temporary set-ups of instruments
Premium Star Chemical element Hydrogen
into existence and how it managed to become what it is today. Hawking also shares the evidence that scientists‚ such as himself‚ have collected through the years. First of all‚ the video discuss that “the universe is constantly expanding… like balloon.” Hawking explains this by a simple demonstration of the Doppler Affect. He explains that on a straight road‚ when a car approaches you at a high rate of speed‚ it appears to be slightly blue. When it moves farther away‚ it appears to be slightly
Premium Universe Atom Hydrogen