Science 9 2nd PT Review (PDF)

Which model of the atoms explains that electrons were confined to specific orbits, each characterized by their own discrete levels of energy? Answer: Bohr’s Model of the Atom His famous gold foil experiment has led to the model of structure wherein it suggested that the atom consis...

Which model of the atoms explains that electrons were confined to specific orbits, each characterized by their own discrete levels of energy? Answer: Bohr’s Model of the Atom His famous gold foil experiment has led to the model of structure wherein it suggested that the atom consisted of a densely packed core of positive charge surrounded by negatively charged electrons. Answer: Ernest Rutherford Which of the atom describes that electrons are not found in specific orbital but are in a cloud? Answer: Quantum Mechanical Model Based on Rutherford’s model of atom, which subatomic particle is present in the nucleus of an atom? Answer: proton only The chemical bond formed when two atoms share electrons is called a(n) ________________ Answer: Covalent bond Which of the following terms is a positively charged ion? Answer: cation A type of chemical bond that is formed from the attraction of an atom that has lost an electron for an atom that has gained an electron is called a(n) ___________________ Answer: Ionic bond. The branch of chemistry that study about the structure, properties, composition, reactions of carbon-containing compound. Answer: Organic Chemistry How many valence electrons does the element carbon has? Answer: Four (4) These are organic compounds that consist of carbon and hydrogen only. Answer: hydrocarbon A property of organic compound that measures the tendency of the substance to evaporate or turn into gaseous state. Answer: volatility In naming hydrocarbon, it is the prefix used if it has ten (10) carbon. Answer: Dec- What do you call the compounds consist of carbon combined with hydrogen, oxygen, nitrogen, halogens, or another carbon? Answer: Organic compounds It is the mass percent of each element in a given compound. Answer:Percentage Composition What formula are you going to use to get the percentage composition in compounds? What does uncertainty principle states? Answer: It is impossible to know the exact position and momentum of an electron. Which of the following statements is NOT true of the Bohr’s Planetary Model? Answer: An electron can absorb or emit a quantity of radiation. Atoms form chemical bonds to _______________ Answer: attain stability. Why can metals be hammered without breaking? Answer: They are malleable. A non-metal atom becomes an ion when it _________________ Answer: gains electrons from a metal. Which of the following is not a carbon compound? Answer: NH2 How many types of bonds are there in the following hydrocarbon? Answer: 2 To which group of hydrocarbon does the given structured molecules below? Answer: Alkenes What will be the name of alkane with four carbon atoms? Answer: Butane When you add all the masses of the atoms in a given substance, what will you get? Answer: Molar mass The complete electron configuration of Argon, element 18, is ________________. Answer: 1s22s22p63s23p6 Which of the following represents the set of quantum numbers to the electrons in 3d8 as its highest energy subshell? Answer: n= 3, l= 2, ml= 0, ml= -1/2 Choose two elements that would likely form an ionic bond among the following elements: Li, Si, F, and Ne. Answer: Li and F Which pair of elements will share their electrons? Answer: H and O Christian is applying something to the ball bearing of the wheels of his bicycles so that the friction will be minimized. Which of the following material do yu think he is using? Answer: lubricating oil Mang Tibo, a fisherman, went home with some of his catch and told his son to cook the fish. But his son said, “Father, the stove ran out of fuel already”. Then his father told him to buy some so that they could start cooking the fish. What do you think the boy would buy? Answer: kerosene Kyla wants to remove her nail polish in both of her hands and toes. What carbon compound can she use? Answer: acetone Protein is one of the classes of an organic compound found in living things. What is its importance/use in living things? Answer: It is used to build, maintain, and repair body tissues. Ethene is a gas produced in plants that acts as a natural ripening agent of fruits. Which organic compound has the identical ability to ripen fruit like ethene? Answer: Ethylene In cold areas, many fish and insects, including the common housefly, produce large amounts of glycerol (C3H8O3 Molar mass= 92.11 g/mol) to lower the freezing point of their blood. How many percent of oxygen is present in glycerol? Answer: 52.11 % In the gold foil experiment by Rutherford, it was observed that most alpha particles pass through undeflected. This result indicates that most of the volume of gold atom consists of __________ Answer: unoccupied space. What is the correct representation of Al atom when it loses three valence electrons? Answer: Al3+ Alkynes has a general formula of CnH2n-2. If n represents the number of carbon and n=5, what is the molecular formula and the name of the alkyne? Answer: C5H8- Pentyne In the problem, “How many atoms are there in 2.45 mol of Cu?” , what is being asked? Answer: The number of atoms in 2.45 mol of Cu. What will most likely to happen to a non-metallic atom after ionic bonding? I. It forms an anion. III. It becomes stable. II. It forms a cation. IV. It becomes unstable. Answer: I & III Which of the following statement best describe how carbon atoms form carbon compound? ANSWER: By sharing their electrons with other non-metal elements. Which of the following pairs of organic compounds is highly flammable? ANSWER: liquefied petroleum gas, kerosene Study the image below. What formula will you use if you are looking the number of moles and the given is the mass of a substance? ANSWER: mass (grams) divided by number of moles How can you apply knowledge on percentage composition? ANSWER: In identifying the correct amount of substance present in a sample.