Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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why is a change in temperature evidence that a chemical change has take…
1. Energy is released as a new substance is created 2. a chemical change
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why is dissolving sugar into water a physical change? they form a compo…
1. They can be separated physically 2. the chemical reaction between the two substances
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1 multiple choice 1 point why is water turning to a gas a physical chan…
1. It is still $H_2O$ 2. $H_2O$ gas
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when scientists think a chemical might be risky, what rule says we need…
Precautionary Principle
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read the final stanza. identify the rhyme scheme by using the drop - do…
Though I am old with wandering: A Through hollow lands and hilly lands: E I will find out where she has gone: F And kiss her lips and take her hands: E And walk among long dappled…
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what is an example of a fortified food? o natural supplements o iodized…
Iodized salt
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question 16 which of the following is the best practice when handling c…
1. Store them in a designated area away from food
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5. explain how gasoline powers an engine? 6. how much air is needed to …
5. Gasoline is ignited in cylinders, combustion pushes pistons converting chemical to mechanical energy. 6. About 14.7 pounds of air for stoichiometric combustion. 7. Carbon dioxi…
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changes to state of matter or phase of matter are what type of change? …
Physical change
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which type of change has occurred if you can reverse the substance back…
A. Physical change
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why does the video say that burning something is a chemical change? bec…
because it cannot be changed back to the original form
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is tearing a piece of paper a chemical or physical change? chemical cha…
B. physical change
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what did the vinegar do to the pennies? made them feel rough made them …
made them shiny
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why do you think vinegar is used in so many experiments for chemical ch…
It is a highly reactive acid.
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since the soap is hydrophobic (afraid of water), it sticks to which kin…
B. fat molecules in milk
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why does the bottle explode? the gas produced from the reaction causes …
The gas produced from the reaction causes the pressure.
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what type of property is dependent on how something reacts with somethi…
B. Chemical Property
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write a p for physical and a c for chemical next to each property below…
11. P 12. P 13. C 14. P 15. C
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1 multiple choice 1 point which one describes a chemical change? someth…
a new substance is made
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the fentanyl crisis is a complex and urgent issue. here are some key qu…
1. Es un analgésico sintético muy potente. 2. Su alta potencia puede causar sobredosis y muerte. 3. Actúa sobre el sistema nervioso central, con efectos como sedación y depresión …
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7. use the triangle to the left to determine the following: what is the…
$20\ g$
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part 1c: describe a feedback loop involving permafrost thaw that includ…
- What is the rate of the chemical reaction between soil carbon and air oxygen? - How much extra carbon dioxide will be generated compared to the initial model? - How will the add…
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temperature plays a role in both physical and chemical changes by influ…
particle energy and movement
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what are some observations that indicate a chemical change? gas formati…
D. All of these options indicate a chemical change
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13/16 what is a chemical change? a change that can be easily reversed b…
A change that involves the formation of new substances with different properties
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match the arrangement to the state of matter
First arrangement - Solid Second arrangement - Gas Third arrangement - Liquid
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which of the following is a change from solid to gas? d) freezing a) me…
B. Sublimation
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what is the phase change from liquid to solid called? freezing melting …
Freezing
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what is a physical change? a change in which the substance retains its …
A. A change in which the substance retains its original properties
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fill in the blank: the process of changing from gas to liquid is known …
condensation
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which of the following is an example of a chemical change? burning wood…
A. Burning wood
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independent practice: write equations in multiple variables practice* m…
$5a + 7b+9c = 300$
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period chemistry worksheet name 1. give the chemical symbol for each of…
1. a. Br; c. Hg; e. F; h. Bi 2. a. Ag; c. Cd; e. Sn; h. Al; d. Sb; f. As 3. a. 2; b. 2; c. 2; d. 3; e. 1; f. 3 4. With OH⁻: Fe(OH)₂, Al(OH)₃, Hg(OH)₂, NH₄OH, NaOH With Cl⁻: FeCl₂,…
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which process represents a chemical change?* 1 point boiling water cutt…
Frying an egg
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what is a key indicator that a chemical change has occurred? * a change…
A change in temperature, color, or a gas forming
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which of the following is a physical change? * 1 point burning wood rus…
C. Breaking glass
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3. (2 pts) the vapor pressure of ethanol is 115 torr at 34.9°c. if δh_v…
$0^{\circ}\text{C}$
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question 8 (1 point) listen the three particles that make up an atom ar…
False
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question 6 (1 point) protons and neutrons are found inside the nucleus …
True
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which subatomic particle has a negative charge and is found outside the…
Electron
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question 4 (1 point) what is the center of an atom called? nucleus prot…
A. Nucleus
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what is chemistry the study of? the study of living organisms the study…
The study of what matter is made of, how it's structured, and how it changes or reacts with other substances
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time and change 5. use map d, new babylonian empire, to sequence the fo…
1. a. Babylonians fail to conquer Egypt. 2. b. Babylonians conquer Nineveh. 3. c. Babylonians conquer Jerusalem. 4. d. Persians attack Babylon. 5. e. Babylonians conquer Carchemis…
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which change is likely to happen to an atom of the element strontium (s…
It will give up electrons, forming a positive ion
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answer the following questions. 1) how many molecules are present in 20…
1. Approximately $7.83\times 10^{23}$ molecules 2. Approximately $19.6$ g 3. Approximately $1.32\times 10^{23}$ molecules 4. Approximately $1.91\times 10^{24}$ molecules 5. Approx…
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how many valence electrons are in an atom of the element fluorine? (1 p…
D. seven
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why do atoms exchange or share electrons during bonding? (1) to obtain …
to obtain a full outer electron shell
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what are valence electrons? (1 point) electrons that are shared between…
the electrons in an atom's outermost energy level
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10)one drop of water weighs 0.040 g. how many molecules are there in on…
10) Approximately $1.33\times 10^{21}$ molecules 11) Approximately $4.63\times 10^{15}$ molecules 12) 3 moles, approximately $1.8066\times 10^{24}$ molecules 13) Approximately $1.…
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which feature defines a neutral atom? (1 point) the ability to change t…
the number of electrons equal to the number of protons
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what is the main style difference between oses\ and ight\? oses\ uses i…
"Roses" uses iambic pentameter.
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avogadros number (6.02 x 10²³) was not discovered by him, but named in …
1. Approximately $4.32$ g 2. $3.18\times10^{23}$ molecules 3. $177.5$ g 4. $76.8$ L 5. $1.806\times10^{24}$ atoms 6. $384.8$ g 7. Approximately $0.0545$ mol 8. Approximately $0.05…
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problem 3: the freezing point of benzene is lowered by 1.2 °c when 1.50…
$128\ g/mol$
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question 15 why does ice stay at the top of oceans instead of sinking t…
Question 15: A. Ice is less dense than liquid water Second question: Water has a high heat capacity
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15. chart of neurotransmitters neurotransmitter function(s) malfunction…
| Neurotransmitter | Function(s) | Malfunction(s) | | ---- | ---- | ---- | | Acetylcholine (ACh) | Muscle - contraction, memory, learning | Alzheimer's disease (low levels) | | Do…
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les miroirs pivotants lorsquon fait pivoter un miroir plan sans changer…
a) Le rayon réfléchi pivote de $10^{\circ}$ car l'angle de pivotement du rayon réfléchi est le double de l'angle de pivotement du miroir. b) La distance séparant l'observateur de …
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doc. 8 excerpts from the suppressed speech of wamsutta, 1970 to have be…
Plymouth's descendants wanted a complimentary, myth - based speech about friendly relations. Wamsutta wanted to expose the injustices like land - taking, attempts to convert and c…
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explain how air pressure changes as you travel away from earths surface…
As you travel further from the Earth's surface through the atmosphere, air pressure decreases because there is less air above exerting weight. This causes gas molecules in the atm…
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make the following conversions. express your answers in scientific nota…
a. $1.48\times 10^{7}\text{ }\mu\text{g}$ b. $3.72\times 10^{0}\text{ g}$ c. $6.63\times 10^{4}\text{ cm}^{3}$ d. $7.5\times 10^{1}\text{ kJ}$ e. $3.9\times 10^{3}\text{ dg}$ f. $…
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in addition to science courses like physics and chemistry, what other t…
B. computer science
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what is an atomic nucleus? a positive charge that is spread throughout …
C. positively charged region at the center of the atom
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true or false 8 there are about 400 known elements 9 all of the element…
8. False 9. True 10. False Extra Credit: Earth, Air, Fire, Water
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7. how many grams of fuctose (c6h12o6) must be dissolved in 419 g of be…
107.4g
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which of the following candidates would be most prepared for a career i…
Sharon, who has a PhD in chemistry and is willing to move to any city for a job
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3. the theory of ______ of matter states that matter cannot be created …
3. conservation 4. Matter 5. volume 6. element 7. properties True or False: False True
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select the lewis structure that most accurately represents selenium dic…
The first structure (top - left in the image) with single bonds between Se and Cl and lone pairs on all atoms is the correct one.
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zinc sulfide is used in glow - in - the - dark face paint. write the ch…
$ZnS$
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q15. what is the volume of the solid in the following picture? mass = 5…
$2.7\ mL$
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because they penetrate the visible surface of a painting, ultraviolet a…
A. It can provide new information about the attributed artist's practices.
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when added to a solution containing a carbon - carbon double or triple …
$KMnO_4$
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radioactive forms of rubidium chloride are used to help doctors evaluat…
$RbCl$
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zirconium(iv) fluoride is used to make special glass for fiber - optic …
$ZrF_{4}$
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strontium oxide was used in the glass screens of cathode - ray tube (cr…
SrO
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ammonium sulfide is a polyatomic ionic compound. when applied to bronze…
$(NH_4)_2S$
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17 which element is in group 3a and period 4? gallium calcium silicon n…
Gallium
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1. what is the most stable group on the periodic table? why is this gro…
1. The noble - gas group (Group 18) is the most stable due to a full outer - electron shell. 2. The most reactive groups are the alkali metals (Group 1) and halogens (Group 17). A…
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match element based on the number of valence electrons a neutral atom w…
Magnesium: 2 valence electrons Argon: 8 valence electrons Oxygen: 6 valence electrons Aluminum: 3 valence electrons Bromine: 7 valence electrons Lithium: 1 valence electron
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ammonium iodide is a polyatomic ionic compound. it was historically use…
$\text{NH}_4\text{I}$
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atomic models protons, electrons, and neutrons are three types of parti…
Sketch each atom as described above with correct number of protons, neutrons in nucleus and electrons in electron - shells.
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iron(ii) carbonate is a polyatomic ionic compound. it is the primary co…
$FeCO_3$
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below, fill the name of the type of chemical reaction displayed by the …
- For "Particles combine to make new one": Synthesis reaction - For "Particle breaks apart": Decomposition reaction - For "Particle combinations changed": Double - displacement re…
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ammonium chloride is a polyatomic ionic compound. it is an active ingre…
$NH_4Cl$
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3 which of the following statement is true about carbon-12 and carbon-1…
Carbon-12 and Carbon-13 have the same number of protons but different number of neutrons.
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12 what is the correct answer for the square? 8 -2 27 9 17 protons: 8 n…
-2
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aluminum phosphide is a binary ionic compound. it is used as a pesticid…
$AlP$
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sodium bromide is a binary ionic compound. it is used to prevent the ov…
$NaBr$
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protons: 8 neutrons: 10 electrons: 10 what is the total charge?
-2
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barium oxide is a binary ionic compound. it is used in special camera l…
$BaO$
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silver bromide is a binary ionic compound. it is used in black - and - …
AgBr
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chapter 12 boiling point elevation practice worksheet 1. what is the bo…
$73.4^{\circ}C$
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suchita is going to make an energy transfer diagram to represent the en…
The arrow for heat is the widest output arrow.
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9 how many neutrons are in li(lithium)? assume that the mass is 7. 10 w…
4
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8 how many protons are in calcium? 2 19 20 40
20
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how many protons are in calcium? 2 19 20 40
20 (corresponding to the third option in the multiple - choice list)
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what is the atomic number of the following element? 10 20 19 39 19 k po…
19
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5 how many valence electrons are in f(fluorine)? 9 10 2 7 6 from the di…
7 Since we can't see the diagram for question 6, we can't answer it. But for question 5, the above is the solution.
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from the below picture, how many valence electrons are present? 5 3 7 2
7
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what is the mass of an atom with 5 protons, 7 neutrons, and 5 electrons…
12
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3 what is the mass of an atom with 5 protons, 7 neutrons, and 5 electro…
12 (corresponding to the fourth option in the first question)
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1 the period number of an element indicate the number of electron energ…
1. number of electron energy levels 2. Electron