Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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1. which of the following is an example of a chemical change? dissolvin…
the rusting of a car
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which of the following statements is true about the elements labeled a …
B - Element A forms a 2 - ion, and element B forms a 1+ ion.
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using the information in the periodic table, how would you rank the ele…
C - Aluminum has more valence electrons than sodium, but fewer than chlorine.
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na br kr ca s ga sb atomic # period group # family name # of valence el…
Na: 11, 3, 1, Alkali metals, 1, 11, Metal, Yes, Solid, +1; Br: 35, 4, 17, Halogens, 7, 35, Non - metal, No, Liquid, - 1; Kr: 36, 4, 18, Noble gases, 8, 36, Non - metal, No, Gas, 0…
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a comanche story: the liberation of buffalo traditional native american…
1. Coyote sends animals to distract the old woman and child, and then a chosen animal howls to scare the buffalo into escaping. 2. The story shows the buffalo were central to the …
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what would happen if.... a proton is added to carbon? a proton is remov…
Adding a proton: Nitrogen. Removing a proton: Boron. Adding a neutron: Different carbon isotope. Removing a neutron: Different carbon isotope. Adding an electron: Negatively - cha…
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a proton is added to carbon? a proton is removed from carbon a neutron …
A proton is added to Carbon? Nitrogen A proton is removed from Carbon? Boron A neutron is added to Carbon? Carbon isotope A neutron is removed from Carbon? Carbon isotope An elect…
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what does ams (accelerator mass spectrometry) do? it uses evolutionary …
# Brief Explanations: For the first question, AMS uses particle accelerators to measure isotopes, aiding in dating organic materials by examining decay. For the second, chronology…
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use the periodic table to select the element from the drop - down menu …
For Mg, possible answers could be elements like Al (if options include it). For P, possible answers could be elements like S. For C, possible answers could be elements like B. For…
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the generalized soil profile below shows a soil with four horizons. whi…
D. O
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the author to her book by anne bradstreet thou ill - formd offspring of…
C. A, A, B, B
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question 3 (1 point) saved listen which of the following is incorrect a…
B. should be washed before and after use
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read the poem oses,\ by george eliot you love the roses—so do i. i wish…
B. "Night" uses a rhyme scheme
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name: _ date: _ forms of energy answer sheet (version 1) questions 1. w…
1. Energy is the ability to do work. An object with energy can cause change. 2. Radiant: Energy carried by electromagnetic waves. Electrical: Energy from electric charge flow. Sou…
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3. (a) a mass of 3.50 g of sodium hydrogen carbonate reacted completely…
(a) $HCO_3^-(s)+H^+(aq) ightarrow CO_2(g)+H_2O(l)$ (b)(i) $0.04\ mol$ (b)(ii) $896\ cm^3$ (c) The limiting reagent is $HCl$. Reason: The mole - ratio of $NaHCO_3$ to $HCl$ in the …
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read the paragraph. 1 ji - yoo is brainstorming topics for a term paper…
sentences 3 and 6
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exercise 1: parts of speech review label each word in the sentence belo…
1. My: ADJ, Grandpa Winston: N, believes: V, tiny: ADJ, scaly: ADJ, lizard: ADJ, people: N, live: V, in: PR, his: ADJ, vents: N 2. He: P, sets: V, traps: N, everyday: ADV, hoping:…
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read the paragraph. 1 alejandros guidance counselor is helping him plan…
D. sentence 4
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read the sentence. 1 alejandros guidance counselor is helping him plan …
C. sentence 3
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why are the trends and exceptions to the trends in ionization energy ob…
B. Ionization energy tends to increase across a period because the nuclear charge increases. C. Ionization energy tends to increase across a period because electrons are added to …
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eden organics provides massages, facials, and organic body treatments. …
A. To the left
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8 multiple choice 1 point for the f sublevel, the number of orbitals is…
C. 7
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scandium nitrogen silicon lithium
Nitrogen
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use the diagram below to answer 14 and 15 14. the type of reaction is u…
reversible
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3 multiple choice 1 point what subatomic particle is located outside th…
D. electrons
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2. ordinary soap bubbles usually exist for a minute or less before popp…
It describes the effects of a process devised by researchers that increases the longevity of an object discussed in the text.
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atomic theory, bohr, and electron configuration test 1 multiple choice …
D. proton
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friendship by ralph waldo emerson (excerpt) there are two elements that…
B. Honesty and authenticity are the foundation for true friendships.
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select all that are compounds. a. o₂ b. kf c. fe d. cl₂ e. ici
B. KF, E. ICl
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3. (a) a mass of 3.50 g of sodium hydrogen carbonate reacted completely…
(a) $HCO^{-}_{3(aq)}+H^{+}_{(aq)} ightarrow CO_{2(g)}+H_{2}O_{(l)}$ (b)(i) $0.04\ mol$ (b)(ii) $896\ cm^{3}$ (c) $HCl$ is the limiting reagent because the amount of $HCl$ will be …
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8. in addition to carbon and hydrogen, a molecule of vegetable oil cont…
B. oxygen
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1. the density of silver (ag) is 10.5 g/cm³. find the mass of ag that o…
$10132.5\ g$ ### 2.
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which of these is the smallest building block of an element? mol molecu…
C. atom
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ernest rutherford built on the atomic theories generated by john dalton…
True
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4. which is an example of an organic compound? c6h12o6 h2o co2 nacl
C6H12O6
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alchemists believed they could turn any substance into gold. o true o f…
True
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2. (a) a white powder, m, dissolves in water to form a solution with a …
(a)(i) Blue litmus paper turns red. (a)(ii) Q is a carbonate. Reason: Acids react with carbonates to produce carbon - dioxide gas. (b) Test: Add sodium hydroxide solution to each …
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2. (a) a white powder, m, dissolves in water to form a solution with a …
(a)(i) The blue litmus paper will turn red. (a)(ii) Solid Q is a carbonate. Reason: Acids react with carbonates to produce carbon dioxide gas, and solution M (an acid) reacts with…
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skill practice 4 numbers practice name:______ date:______ 1. solve the …
a) $2.229\times 10^{8}$ b) $8.07\times 10^{6}$ c) $5.415\times 10^{20}$ d) $1.124142\times 10^{7}$ e) $2.976\times 10^{12}$ f) $7.717\times 10^{3}$ 2. a) $2.300021\times 10^{10}$ …
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d. can you prepare 1 liter of a 0.5 - molar glucose solution? show your…
Yes, by weighing 90 g of glucose and dissolving it in enough water to make 1 liter of solution. ### e.
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in round numbers of daltons, sucrose has a molecular mass of daltons. b…
342; 342
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in round numbers of daltons, sucrose has a molecular mass of daltons. b…
342
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element mass of atom total # of atoms total mass of atoms o 16 daltons …
$342$
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which particle diagram most likely shows carbon dioxide gas? ○ a. ○ b. …
C.
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which particle diagram most likely shows carbon dioxide gas? o a. o b. …
C.
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a chemical equation is shown below. al + o₂ → al₂o₃ which is the correc…
D. $4Al + 3O_2 ightarrow2Al_2O_3$
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four beakers and their contents are listed below. beaker mixture 1 suga…
C. Beaker 3
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consider the chemical reaction below. c₃h₈ + 5o₂ → ? co₂ + 4h₂o how wou…
B. Place a coefficient of 3 before the $CO_2$.
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which best illustrates the arrangement of atoms in an element? a. image…
B.
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1. (a) table 1 is an incomplete table showing pollutants from the pro s…
(a)(i) Particulate matter; Using electrostatic precipitators (ii) Nitrogen oxides; Using selective catalytic reduction (SCR) (b)(i) Yeast acts as a biological catalyst to convert …
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read the passage and answer the following question(s). water formation …
D. The number of hydrogen atoms and oxygen atoms is the same before and after the reaction, so the mass does not change during the reaction.
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read the passage and answer the following question(s). water formation …
Reactant: $O_2$, $H_2$ Product: $H_2O$
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read the passage and answer the following question(s). water formation …
C.
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read the passage and answer the following question(s). passage 5143 dir…
C. chemical reaction, because the solution changed color.
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next, the teacher adds zinc granules to the test tube and places the st…
B. A large amount of heat and light is released when the bubbles pop.
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which table correctly matches each particle with its location and charg…
C. proton: in the nucleus, positive; neutron: in the nucleus, neutral; electron: around the nucleus, negative
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3 formula 5 points suppose a meal gives 327.0 cal of chemical potential…
$1.367168\times 10^{6}$ J
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there are answer naturally - occurring elements. seventy - five percent…
92, hydrogen, oxygen, compounds, 20 million, year
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10. place les lettres a à g au bon endroit sur le tableau périodique ci…
A: 20 (4e période, 2e colonne) B: 9 (2e période, 17e colonne) C: 2 (1re période, 18e colonne) D: 5 (2e période, 13e colonne) E: 49 (5e période, 13e colonne) F: 52 (5e période, 16e…
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activité : elemento! 1. quel élément a 2 électrons de valence et 3 nive…
# Explications succinctes: 1. Un élément ayant 2 électrons de valence et 3 niveaux électroniques est le magnésium (Mg). Le nombre de protons est égal au nombre d'électrons dans un…
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activité : casse - tête du tableau périodique complète le tableau suiva…
| Nom de l'élément | Masse atomique | Numéro atomique | # de protons | # de neutrons (STE) | # d'électrons | | ---- | ---- | ---- | ---- | ---- | ---- | | Mercure | 80 | 80 | 80 |…
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1. what is at the center of every atom? a. an electron b. a compound c.…
1. d. A nucleus 2. b. Protons and neutrons 3. c. Electrons circle the nucleus and have a negative charge 4. a. The number of electrons 5. b. The number of protons 6. a. A molecule…
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11th grade chemistry homework name: period: date: topic: basics of the …
1. A. Period 2. D. Metal 3. B. Group (or Family) 4. E. Nonmetal 5. C. Atomic Number
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short response (5 points) choose one of the following prompts and write…
Option A: The periodic table is a useful tool in chemistry because it organizes elements based on their atomic number and electron - shell structure. Elements in the same group ha…
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1. what is the atomic number of oxygen? 2. which element is in group 1,…
8 2.
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16. a box having the dimensions, 14 cm by 8.0 cm by 3.0 cm is filled wi…
336 g
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2. c is a mixture of two compounds. carry out the following exercises o…
Based on the above tests, observations such as color - changes, precipitate formation or dissolution, and gas evolution need to be recorded to identify the components in the mixtu…
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1. solve each of the following equations for x. a. 2x + 4 = 10 b. 5x = …
a. \(x = 3\) b. \(x = 7\) c. \(x = 2\) d. \(x=\frac{2}{5}\)
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7) choose the best answer. open - toed shoes and ____ should not be wor…
7) D. sandals 8) A. gloves 9) B. waft
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4) choose the correct safety measure for the scenario. you spill chemic…
4. safety shower 5. Goggles 6. chemicals
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1) choose the correct safety measure for the scenario. you spill a chem…
1. D. eyewash station 2. C. fire blanket 3. B. fume hood
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enthalpy and phase changes 273\tfreeze liquid\t$delta h_{fusion}=40.7\f…
Since we made assumptions for illustration: $q_1$: Unknown (need more data) $q_2$: $40.7kJ$ $q_3$: $-0.02093kJ$ $q_{tot}$: $40.67907kJ$ (assuming $q_1 = 0$)
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calculate the amount of heat released when 27.0 g h₂o is cooled from a …
Cool liquid from 314 K to 273 K, freeze liquid at 273 K, and cool solid to 263 K.
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answer all questions. all your burette readings (initial and final) as …
(a) Follow the titration procedure as described, record readings and calculate average volume of $A$ used. (b) $H_2C_2O_4 + 2NaOH ightarrow Na_2C_2O_4+2H_2O$ (c)(i) Depends on tit…
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consider the following salts: pb(no3)2; (nh4)2so4; cuco3 and nahco3. wh…
(i) $CuCO_3$; (ii) $CuCO_3$; (iii) $CuCO_3$; (iv) $Pb(NO_3)_2$; (v) $Pb(NO_3)_2$
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the molar heat of vaporization of hydrogen fluoride (hf) is 31.18 kj/mo…
B. - 155.8 kJ
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a chemical engineer needs to calculate the amount of coolant required t…
$\Delta H_{vap}$
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a scientist needs to calculate the amount of heat released when a sampl…
$-\Delta H_{fus}$
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question two (organic chemistry) 10 marks draw the condensed structural…
1. Condensed structural formula of 3 - ethyl - 2,4,5 - trimethylheptane: $CH_3CH(CH_3)CH(C_2H_5)CH(CH_3)CH(CH_3)CH_2CH_3$ 2. Condensed structural formula of 1 - isopropyl - 3 - me…
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section b: answer all the questions question one (chemical kinetics) 10…
For the first part, $k\approx6.39\times 10^{-4}\ s^{-1}$. For the second part, $t_{1/2}\approx1119\ s$ and $t\approx3698\ s$.
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question 8 (1 point) for the composition notebook exercise in this lab,…
C. $NaHCO_3$
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what is a key difference between chemical and nuclear reactions? in che…
B. Chemical reactions involve electron rearrangements. Nuclear reactions involve changes to the nucleus.
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how can a scientist assess whether a pure niobium (nb) sample is respon…
C. Heat the niobium, and see if the level of radioactivity in the lab increases. D. Place the niobium under pressure, and see if the level of radioactivity in the lab increases.
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what is the basic unit of matter? atom molecule gas compound
A. atom
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which statement correctly describes glucose (c₆h₁₂o₆)? it is made of ma…
It is a compound made of twenty - four total atoms.
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which of these elements is found in both carbohydrates and water? carbo…
Oxygen
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which substance is a compound? water gold oxygen hydrogen
water
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which term describes a pure substance that is made up of only one type …
D. element
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question 3 grade 11 learners are conducting an experiment in a school l…
A mole is the amount of substance that contains as many elementary entities as there are atoms in exactly 12 g of carbon - 12. ### 3.2
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match each part of the client service process with its purpose. some pa…
- "Help your client through the scheduling and payment process by offering rebooking dates": Pre - service - "Accomplish the actual service the client has requested like haircut, …
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question 3 grade 11 learners are conducting an experiment in a school l…
A mole is the amount of substance that contains as many elementary entities as there are atoms in exactly 12 g of carbon - 12. ### 3.2
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1. calcium reacts with a certain element to form a compound with the ge…
b. $Na_2X$
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example: sodium and phosphorus form an ionic compound. what is the mole…
$Na_3P$
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1. for each of the following pairs of elements choose the at with: a. h…
a. F, b. Na, c. F
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write the ground state electron configuration for arsenic.
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p³
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the main component of egg shells is the compound calcium carbonate, cac…
95.1%
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fill in the blanks to create the lesson question, which is the broad qu…
Hypothesis: If a fixed amount of gas is heated, then the volume will increase because the heat will cause the molecules of gas to move faster.
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a gaseous sample of a pure, unknown element is analyzed using a photoel…
Without the actual values from the spectrum (binding energies and number of electrons at each energy level), we cannot complete the ground - state electron configuration, determin…
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a gaseous sample of a pure, unknown element is analysed using a photoel…
Without the actual values from the photoelectron spectrum (binding energies and peak intensities), specific numerical answers cannot be provided. But the general steps to solve ar…
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a certain sugar used in treating patients with low blood sugar has the …
$C_6H_{12}O_6$