Mendeleev proposed the existence of an unknown element that he called eka-aluminum. The element is now called: w) magnesium x) silicon y) gallium z) germanium

1 Answer

Answer :

ANSWER: C -- GALLIUM

Related questions

Description : Why are isotopes not considered in Mendeleev’s periodic table?Name the elements which are predicted by Mendeleev as eka –silicon and eka –aluminum

Last Answer : Ans.Because Mendeleev gave priority to similarities in properties. Germanium and gallium

Description : Which of the following elements replaced eka-Aluminium in Mendeleev's Periodic Table? (1) Scandium (2) Gallium (3) Titanium (4) Germanium

Last Answer : (2) Gallium

Description : Which of the 3rd period elements loses electrons most readily? w) Sodium x) Magnesium y) Aluminum z) Silicon

Last Answer : ANSWER: A-SODIUM

Description : Which of the following metals is a solid at room temperature, yet melts in your hand? w) gallium x) cesium y) sodium z) magnesium

Last Answer : ANSWER: W -- GALLIUM

Description : Which of the following metals melts in your hand? w) gallium x) cesium y) sodium z) magnesium

Last Answer : ANSWER: W -- GALLIUM

Description : Tunnel diode is a: a) Power diode b) Has light doping c) Has heavy doping d) Is a reverse recovery diode Ans: C 76.LEDs are fabricated from: a) Silicon b) Germanium c) Si or Ge d) Gallium arsenide

Last Answer : Ans: D

Description : What kind of battery panels are used in some advance satellites? A. Gallium Arsenide solar panel B. Germanium based panels C. Silicon based panels D. Gallium Phosphate solar panel

Last Answer : A. Gallium Arsenide solar panel

Description : Which of the following is the element which makes up about 8 percent of the earth's crust and occurs in all rocks except limestone and sandstone? w) sulfur x) aluminum y) sodium z) magnesium

Last Answer : ANSWER: X -- ALUMINUM

Description : Which element is associated with the term "galvanized"? w) gallium x) zinc y) mercury z) nickel

Last Answer : ANSWER: X -- ZINC

Description : Some physicians suggest that women supplement their diets with antacids to supply additional amounts of a certain element thought to reduce the risk of osteoporosis. The ingredient in antacids which ... element is: w) calcium carbonate x) aluminum hydroxide y) magnesium hydroxide z) simethicone 

Last Answer : ANSWER: W -- CALCIUM CARBONATE

Description : Which of the following groups of elements have an OUTER ELECTRONIC configuration of S-2-P-2? w) halogens x) Nitrogen-Phosphorus Group y) Carbon-Silicon Group z) Boron-Aluminum Group

Last Answer : ANSWER: Y -- CARBON-SILICON GROUP

Description : Which of the following substances would be the best choice to neutralize aqueous Sodium Hydroxide? w) sodium carbonate x) silicon dioxide y) aluminum oxide z) phosphorus pentoxide

Last Answer : ANSWER: Z -- PHOSPHORUS PENTOXIDE

Description : Which of the following elements was unknown to ancient civilizations? w) tin x) aluminum y) mercury z) sulfur

Last Answer : ANSWER: X -- ALUMINUM

Description : Thermite is a mixture of aluminum and: w) hematite x) sodium oxide y) iron z) magnesium

Last Answer : ANSWER: W -- HEMATITE

Description : Which of the following elements gains electrons most readily? w) Sodium x) Magnesium y) Aluminum z) Fluorine

Last Answer : ANSWER: D -- FLUORINE

Description : Which of the following elements would form an acid oxide with the formula XO2 and an acidic compound with hydrogen with the formula XH2? w) Sodium x) Magnesium y) Aluminum z) Sulfur

Last Answer : ANSWER: Z -- SULFUR

Description : Which of the listed pairs of materials make the best insulators? A. copper and aluminum B. glass and mica C. dry air and a vacuum D. doped silicon and germanium

Last Answer : Answer: B

Description : Steel is composed of a number of elements. The two essential elements are iron and w) aluminum x) carbon y) nickel z) silicon 

Last Answer : ANSWER: X -- CARBON

Description : Name the person who developed a table of elements which revealed regularities in elemental properties in 1869? w) Theodore Richards x) Antoine Lavoisier y) Dmitri Mendeleev z) Svante Arrhenius

Last Answer : ANSWER: Y -- DMITRI MENDELEEV

Description : Which of the following scientists was awarded the Nobel Prize in 1911 for the discovery of the radioactive elements, radium and polonium? w) John Dalton x) Dmitri Mendeleev y) Emil Fischer z) Marie Curie

Last Answer : ANSWER: Z -- MARIE CURIE

Description : The existence of an element in two or more forms i the same physical phase is known as: w) allotropy x) diphasisty y) polyformation z) diatomic existence

Last Answer : ANSWER: W -- ALLOTROPY

Description : In which form is Silicon most frequently found in nature? w) The free element Silicon x) Silicon-Oxygen compounds y) Silicon-Carbon compounds z) Silicon-Metal compounds

Last Answer : ANSWER: X -- SILICON-OXYGEN COMPOUNDS

Description : What is the only non-metal element that is a liquid at room temperature and one atmosphere? w) bromine x) argon y) silicon z) selenium

Last Answer : ANSWER: W -- BROMINE

Description : Which of the following elements is found in the earth's crust as both a native element and as a compound? w) argon x) copper y) chlorine z) silicon

Last Answer : ANSWER: X -- COPPER

Description : Which of the following is the only element which i "mined" from the sea? Is it: w) copper x) magnesium y) uranium z) zinc

Last Answer : ANSWER: X -- MAGNESIUM 

Description : Which of the following is an important element of stainless steel. w) chromium x) magnesium y) copper z) nickel  

Last Answer : ANSWER: W -- CHROMIUM  

Description : Who proposed first atomic theory? (1) E. Rutherford (2) De Broglie (3) John Dalton (4) D. I. Mendeleev

Last Answer : (3) John Dalton Explanation: Democritus first suggested the existence of the atom but it took almost two millennia before the atom was placed on a solid foothold as a fundamental chemical object by John Dalton (1766-1844).

Description : Whose name is given to alkylmagnesium halides: w) Victor Grignard x) Daniel Rutherford y) Dmitri Mendeleev

Last Answer : ANSWER: W -- VICTOR GRIGNARD

Description : Name two elements that find wide application in transistor industry – (1) Silicon and Germanium (2) Carbon and Platinum (3) Iridium and Germanium (4) Tungsten and Platinum

Last Answer : (1) Silicon and Germanium Explanation: A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. Semiconductor material (date first used): the metalloids ... -germanium (1989), the allotrope of carbon graphene (research ongoing since 2004), etc.

Description : Name two elements that find wide application in transistor industry (1) Silicon and Germanium (2) Carbon and Platinum (3) Iridium and Germanium (4) Tungsten and Platinum

Last Answer : Silicon and Germanium

Description : Which of the following elements does not occur in nature as a native ore? w) silver x) gold y) platinum z) aluminum

Last Answer : ANSWER: Z -- ALUMINUM

Description : Which of the following metals is obtained from its most common ore using an electrolytic process? w) nickel x) tin y) aluminum z) manganese

Last Answer : ANSWER: Y -- ALUMINUM

Description : Which of the following elements would form a covalent bond with Bromine? w) Calcium x) Aluminum y) Oxygen z) Tin

Last Answer : ANSWER: Y -- OXYGEN

Description : Which of the following metals is LEAST reactive toward atmospheric oxygen? w) Lead x) Copper y) Iron z) Aluminum

Last Answer : ANSWER: X -- COPPER

Description : This noncombustible liquid in its dry form is noncorrosive to common metals except aluminum. About 90% of all of this material which is manufactured goes into the production of chlorofluorocarbons. ... substance: w) carbon tetrachloride x) methylene chloride y) hydrogen chloride z) methyl fluoride

Last Answer : ANSWER: W -- CARBON TETRACHLORIDE

Description : Which one of the following atoms has two unpaired electrons in its ground state: w) Sodium x) Calcium y) Oxygen z) Aluminum

Last Answer : ANSWER: Y -- OXYGEN

Description : Which of the following Greek philosophers proposed the first atomic theory around 400 B.C.? Was it w) Plato x) Archimedes y) Aristotle z) Democritus

Last Answer : ANSWER: D -- DEMOCRITUS

Description : It is the made from semiconductor material such as aluminum-galium-arsenide or gallium-arsenide-phosphide. A. APD B. Injection laser diode C. Light emitting diode D. Positive-intrinsic-negative

Last Answer : C. Light emitting diode

Description : Which of the following substances would be the best choice to neutralize sulfuric acid? w) sodium hydroxide x) silicon dioxide y) copper metal z) phosphorus pentoxide

Last Answer : ANSWER: W -- SODIUM HYDROXIDE

Description : Which of the following elements would most likely be a silvery solid at room temperature? w) Sodium x) Silicon y) Selenium z) Astatine

Last Answer : ANSWER: W -- SODIUM

Description : Which of the following is not a covalent network solid? w) silicon dioxide x) silicon oxide y) boron nitrate z) sodium oxide

Last Answer : ANSWER: D -- SODIUM OXIDE

Description : In commercial vulcanization, crosslinking is introduced by the addition of: w) sulfur x) toluene y) silicon z) phosphorus

Last Answer : ANSWER: W -- SULFUR

Description : The element used for making solar cells is - (1) Magnesium (2) Sodium (3) Calcium (4) Silicon

Last Answer : (4) Silicon Explanation: Materials presently used for photovoltaic solar cells include mono-crystalline silicon, polycrystaijhne silicon, amorphous silicon, cadmium telluride, and copper indium selenideisulfide.

Description : What is the element that is in the highest percentage in the composition of the earth? (1) Silicon (2) Oxygen (3) Magnesium (4) Iron

Last Answer : (2) Oxygen Explanation: Earth, our home, is the third planet from the sun. It is the only planet known to have an atmosphere containing free oxygen, oceans of liquid water on its surface, and, of ... of it in the oceans. About a fifth of its atmosphere is made up of oxygen, produced by plants.

Description : The element used in the manufacture of safety matches is – (1) Phosphorous (2) Magnesium (3) Silicon (4) Sulphur

Last Answer : (1) Phosphorous Explanation: One end of a match is coated with a material that can be ignited by frictional heat generated by striking the match against a suitable surface. The coated end ... ," contains either phosphorus or phosphorus sesquisulfide as the active ingredient and gelatin as a binder.

Description : The element used for making solar cells is (1) Magnesium (2) Sodium (3) Calcium (4) Silicon

Last Answer : Silicon

Description : The element used in the manufacture of safety matches is (1) Phosphorous (2) Magnesium (3) Silicon (4) Sulphur

Last Answer : Phosphorous

Description : What is the element that is in the highest percentage in the composition of the earth ? (1) Silicon (2) Oxygen (3) Magnesium (4) Iron

Last Answer : Oxygen

Description : Which of the following metals is least subject to oxidation? w) silver x) gold y) magnesium z) nickel

Last Answer : ANSWER: X -- GOLD

Description : Which one of the following metals is essential to the structure and functioning of hemoglobin? w) copper x) magnesium y) tin z) iron

Last Answer : ANSWER: Z -- IRON