Chemistry

Suppose that a TLC plate is spotted with samples 1.0 cm above the bottom of the plate. Select the consequence of inserting the plate into a developing chamber containing a pool of developing solvent that is 1.2 cm deep (a) The compounds in the samples will leach into the pool of developing solvent resulting in poor resolution. (b)The pencil marks will dissolve into the developing solvent. (c)The increased capillary action will cause the compounds to migrate up the plate more quickly. (d)The increased depth of developing solvent will result in better resolution of the compounds in each sample.
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The Tacoma narrows bridge collapsed due to?A. RefractionB. ReflectionC. DiffractionD. Resonance
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an atom has 79 protons, 78 electrons and a mass number of 118. how many neutrons does this atom have
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How many grams of lithium hypochlorite (LiClO) are there in 0.649 mol ?
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8. What is Planck's law?O F = hmO F = MAO E = hfO E = mc (squared)
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What type of energy transformation is happening?a boy sliding his foot across the floorA Electrical energy is created by friction when his foot slides across the floor.B The mechanical energy of his foot moving across the floor is transformed into chemical energy.C When his foot is sliding across the floor, it creates heat energy through friction.D When his foot rubs against the floor, the energy of motion changes into light energy.
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Which example best demonstrates stewardship of the atmosphere
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What happens to energy when frequencyis reduced by one half?Energy is doubledEnergy is squaredEnergy is halvedEnergy remains constant
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Which statement best describes the difference between veins and arteries? *veins carry oxygen rich blood back to the heart while arteries carry oxygen poor bloodaway from the heartveins carry oxygen poor blood back to the heart while arteries carry oxygen rich bloodaway from the heart.brings oxygen into the lungs and releases carbon dioxide and water (waste materials)from the bodyarteries carry blood that is carbon dioxide rich to the heart,
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Which sample matter is a pure substance
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Which of the following is a process that changes the composition of rocks from one material to another? (3 points) a Erosion b Deposition c Physical weathering d Chemical weathering
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Which term describes this molecular shape?A. Tetrahedral B. BentC. Trigonal planar D. Linear
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how would you differentiate between acid and bases if the list of their chemical formula is given to you
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Annalise observes a streak of light in the sky and says she is seeing a shooting star. What is she most likely observing?a falling staran asteroida meteora dwarf planet
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HELPPPP I WILL GIVE YOU BRAIN THINGG WHATEVER ITS CALLED We have learned that there are five steps to reading a new piece of music. Can you name all five steps?
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Isotopes haveQuestion 1 options:A) different numbers of both protons and neutrons in their nuclei.B) a different number of neutrons in their nuclei.C) a different number of protons in their nuclei.D) a different number of electrons.Question 2 (5 points) An aqueous solutionQuestion 2 options:A) must contain three or more substances.B) is a single-phase heterogeneous mixture.C) has water as the solvent.D) has water as the solute.Question 3 (5 points) Which of the following is a homonuclear diatomic molecule?Question 3 options:A) NH3B) COC) 2CO2D) H2Question 4 (5 points) Given a container of a solution of 5% HCl, all samples tested from this same bottle will have the same mass ratio of hydrogen to chlorine. This is an application ofQuestion 4 options:A) the law of conservation of energy.B) the law of multiple proportions.C) the law of conservation of mass.D) the law of constant composition.Question 5 (5 points) Elements in the same periodQuestion 5 options:A) have the same principal quantum number.B) form bonds with the same type of elements.C) have the same number of valence electrons.D) have the same number of protons.Question 6 (5 points) Which of the following contribute(s) to most of the mass of an atom?Question 6 options:A) Neutrons onlyB) Protons and neutronsC) Protons and electronsD) Protons onlyQuestion 7 (5 points) In a certain chemical reaction, the bonds of the products contain more energy than the bonds of the reactants. For the reaction to occur, which of the following best describes what occurred?Question 7 options:A) Energy was released, so the reaction is endothermic.B) Energy was released, so the reaction is exothermic.C) Energy was added, so the reaction is endothermic.D) Energy was added, so the reaction is exothermicQuestion 8 (5 points) A solutionQuestion 8 options:A) is a single-phase homogeneous mixture.B) must contain water.C) is always a liquid.D) can contain more than two phases.Question 9 (5 points) Which of the following is true of alloys?Question 9 options:A) They can only be composed of metals.B) They must be held together by chemical bonds.C) They're liquid solutions.D) They must contain a metal.Question 10 (5 points) Which of the following best describes an atomic number? An element's identity is defined by its atomic number; this means it represents the number ofQuestion 10 options:A) electrons in the element.B) neutrons in its nucleus.C) protons plus neutrons in its nucleus.D) protons in its nucleus.Question 11 (5 points) Electrons in the outermost shell of an atom that are available to bond with the electrons of other atoms areQuestion 11 options:A) cations.B) free electrons.C) valence electrons.D) anions.Question 12 (5 points) Main group elements have valence electrons in which suborbitals?Question 12 options:A) d and fB) s and pC) p and fD) s and dQuestion 13 (5 points) Molecules haveQuestion 13 options:A) only kinetic energy.B) only potential energy.C) both potential and kinetic energy.D) neither kinetic nor potential energy.Question 14 (5 points) The majority of elements areQuestion 14 options:A) metalloids.B) nonmetals.C) metals.D) inert.Question 15 (5 points) A student found the mass of an object to be 26.5 g. To find the volume, the student submerged the object in a graduated cylinder of water. Submerging the object in the water in the graduated cylinder increased the water level by 24.1 mL. The density of the object isQuestion 15 options:A) 1.0906 g/mL.B) 0.909 g/mL.C) 1.10 g/mL.D) 1.1 g/mL.Question 16 (5 points) Mass and energy are conservedQuestion 16 options:A) only in chemical changes.B) in chemical changes and physical changes.C) always in physical changes and sometimes in chemical changes.D) only in physical changes.Question 17 (5 points) Which of the following can't be broken down any further chemically?Question 17 options:A) CompoundsB) ElementsC) MatterD) MoleculesQuestion 18 (5 points) A/an _______ is the smallest unit of matter that has the characteristics of a chemical element.Question 18 options:A) atomB) protonC) moleculeD) electronQuestion 19 (5 points) The distance between consecutive peaks or troughs in a wave isQuestion 19 options:A) frequency.B) displacement.C) amplitude.D) wavelength.Question 20 (5 points) The phase transition of dry ice (frozen carbon dioxide) to gas is an example ofQuestion 20 options:A) condensation.B) sublimation.C) deposition.D) vaporization.I WILL GIVE BRAINLIEST IF YOU CAN ANSWER THEM
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Lollll I need help with this question
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Rain is falling at 2.00 inches per hour. How many inches have fallen in 6000.0 seconds?
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What is the molecular geometry of the atoms bonded to the carbon atom indicated with arrow I in this structure of caffeine?
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Which of the following molecules has a trigonal pyramidal shape?CONi ---COA.OBCI-S cXeoO.O C.0-N
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in a hydraulic lift system, the output force is greater than the input force because
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NEED HELP FAST!!!! Points A and B are locations on the banks of a river. What are the dominant processes occurring at locations A and B? * A. deposition at location A; erosion at location BB. erosion at location A; deposition at location BC. deposition at both locations A and B D. Erosion at both locations A and B
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Calculate number of moles in 42g of silicon.
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