化学
化学反应、化学计量、分子结构与元素性质。
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what is the overall energy transformation in a coal - fired power plant…
chemical to electrical
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the formation of photochemical smog is a result of a series of reaction…
A. evaporation from gasoline
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a) 1s²2s²2p⁶3s³3d⁵ -
# Explicación: ## Paso 1: Recordar reglas de orbitales Los orbitales $s$ admiten máximo 2 electrones. ## Paso 2: Identificar error en el orbital El término $3s^3$ es inválido, ya …
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pebworth, logan sps_physical science_checkpoint2_2025-2026 23 of 40 pla…
1, 3, 2 (in order for $\text{C}_2\text{H}_4$, $\text{O}_2$, $\text{CO}_2$)
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directions: why does neon (group 18) rarely form compounds with other e…
C. It is already chemically stable because its outer energy level is full.
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directions: select the equations that correctly demonstrate the law of …
$2H_2 + O_2 \to 2H_2O$ $C + O_2 \to CO_2$
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directions: an unknown element from group 1 reacts with an element from…
B. An ionic bond is formed because the metal loses an electron to the nonmetal.
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directions: look at the formula for glucose: $c_6h_{12}o_6$ which of th…
- There are a total of 24 atoms in one molecule of glucose. - There are exactly 12 hydrogen atoms in the molecule. - The ratio of Carbon to Oxygen atoms is 1:1.
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7. which of the following is true about isotopes? a) they have differen…
c) They have different numbers of neutrons. ### Question 8
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1. which of the following is a characteristic of an ion? a) it has no c…
B. It has either a positive or negative charge. ### Question 2
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the table lists two experiments performed using aluminum foil. | experi…
Experiment 1 shows a physical change because the aluminum curls up due to heat. Experiment 2 shows a chemical change because a new substance forms on the aluminum.
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mixing baking soda and vinegar makes the temperature of the solution de…
New elements were formed.
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pebworth, logan sps physical science checkpoint2 2025 - 2026 directions…
B. Electrostatic forces between positive and negative charges
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pebworth, logan sps_physical science_checkpoint2_2025-2026 question: a …
An element located on the far left side.
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multiple-choice question what is compost? water and soil used to help f…
B. Mixture of organic matter mixed with earth materials like dirt or woodchips.
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the empirical formula of hydroquinone is shown below. the molar mass of…
2. \( C_6H_6O_2 \)
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1. to avoid a possible burn when opening the oven, you should stand: a.…
1. A. TO THE SIDE OF THE OVEN. 10. B. A SHARP KNIFE 11. A. WIPE IT UP IMMEDIATELY. 12. C. WITH THE SIDE OF THE LID AWAY FROM YOU. 13. C. KEEP KNIVES SHARP AND USE THE APPROPRIATE …
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after six years of successional time, about how much organic mass is pr…
410 g/m^2/yr
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1. atomic structure | description | atomic number | mass number | net c…
# Explanation: --- ### Parte 1: Estructura Atómica ## Paso 1: Calcular número atómico El número atómico es igual al número de protones ($p^+$). ## Paso 2: Calcular número de masa …
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applying theory to practice 1. when we say an ion has a positive charge…
1. A positive ion has more protons than electrons, having lost one or more electrons. 2. For ions, "opposites attract" means positively charged ions (cations) are attracted to neg…
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question 2. classify the reaction in each of the following equations: a…
a) Double-displacement reaction b) Synthesis reaction c) Combustion reaction d) Decomposition reaction e) Single-displacement reaction
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in 1899, swedish chemist svante arrhenius developed an equation to answ…
A. remains
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practice: isotope calculations #2 1. complete the following table. | is…
### Part 1: Completing the Table To complete the table, we use the following relationships: - **Atomic Number (\(Z\))** = Number of Protons = Number of Electrons (in neutral atoms…
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15. how many grams are equal to 0.11 mole of copper(i) chromate, $\\ce{…
27 grams (or 26.74 grams for more precision)
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periodic table name: jaydin milladate: section 1 use the following clue…
1. Atomic number: 9; 2. Mass number: 19; 3. Valence electrons: 7; 4. Period: 2; 5. Electron configuration: 2,7; 6. Classification: non - metal; 7. Name: Fluorine; 8. Symbol: F ###…
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quiz instructions question 7 4 pts find the pairs. organic: no more tha…
(for the dropdowns shown): - low fat: must have 3 grams of fat or less per serving - lite: must have either 1/2 fewer calories or 50% less fat
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quiz instructions question 7 4 pts find the pairs: organic: no more tha…
To solve this matching problem, we analyze each term and its corresponding definition: ### 1. Organic The definition for "organic" relates to food production without synthetic inp…
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quiz instructions question 7 4 pts find the pairs: organic no more than…
must have 0.5 grams or less of fat per serving
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started jan 15 at 7:44am quiz instructions question 7 4 pts find the pa…
must have 0.5 grams or less of fat per serving If for "low fat":
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choose the complete ground - state electron configuration for neutral r…
[Kr] 5s1
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choose the complete ground - state electron configuration for the alumi…
B. 1s2 2s2 2p6 3s2 3p1
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use dimensional analysis for each problem. how many kilograms are equal…
B. $1.6 \times 10^{-2}\ \text{kg}$
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which of the following are potential hazards which you might encounter …
infectious microorganisms open flames hot surfaces corrosive chemicals sharp tools or broken glass
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al₂o₃ → al + o₂ cl₂ + nabr → nacl + br₂ h₂ + n₂ → nh₃ na + br₂ → nabr c…
Decomposition ### 2. $\ce{Cl_{2} + NaBr -> NaCl + Br_{2}}$
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part i. complete the table identifying the five reaction types (use the…
s for Part II: 1. $\text{P} + \text{O}_2 ightarrow \text{P}_4\text{O}_{10}$: Rxn Type: $\boldsymbol{\text{S (or C)}}$ (if we take synthesis: S, if combustion: C. But based on the …
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determining the combustion of methane gas conclusion initial mass: 1.00…
The reaction is mostly incomplete combustion.
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determining the formation of an iron chloride experimental data for rea…
4.54 g FeCl₂
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determining the decomposition of nahco₃ conclusion initial mass: 7.53 g…
The correct reaction is the one with the equation \( 2\text{NaHCO}_3(\text{s}) ightarrow \text{Na}_2\text{O}(\text{s}) + 2\text{CO}_2(\text{g}) + \text{H}_2\text{O}(\text{g}) \) (…
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determining the decomposition of nahco₃ experiment introduction alexand…
B. solid
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determining the formation of a tin nitride compound conclusion the expe…
Statement III
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determining the formation of a tin nitride compound experimental data f…
2.16 g Sn₃N₂ (corresponding to the option "2.16 g Sn₃N₂")
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determining the formation of a sulfur oxide conclusion initial mass: 5.…
\( \text{S}_5\text{N}_6 \) (the option with \( \text{S}_5\text{N}_6 \))
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part 2 use electron dot diagrams to show the ionic bonding in the follo…
### PART 2 (Ionic Bonding Formulas): 1. Barium oxide: $\text{BaO}$ 2. Calcium chloride: $\text{CaCl}_2$ 3. Aluminum oxide: $\text{Al}_2\text{O}_3$ 4. Sodium oxide: $\text{Na}_2\te…
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question #4 ethanol, a liquid at room temperature, is the intoxicating …
\( 2.42 \) (rounded to two decimal places, or more precisely \( 2.418 \)) \(\frac{\text{J}}{\text{g}^\circ\text{C}}\)
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the way we measure the amount of matter in a sample is by using a balan…
Primera línea en blanco: masa Segunda línea en blanco: constante (o "la misma")
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an element with mass 730 grams decays by 28.8% per minute. how much of …
22.0 grams
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question 10 of 10 what will occur when the following chemical reaction …
D. The concentration of \(H_2O\) will reach its maximum. (Wait, no—correction: The correct answer is C. Wait, no, re - checking: Wait, the correct analysis: In dynamic equilibrium…
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photosynthesis and cellular respiration $6\\ce{co_{2}} + 6\\ce{h_{2}o} …
B. Product
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determining the formation of an iron chloride experiment introduction d…
B. \( \text{Fe}^+ \)
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determining the formation of a tin nitride compound experiment introduc…
B. \( \text{Sn}_3\text{N}_2 \) and \( \text{Sn}_3\text{N}_4 \)
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determining the formation of an iron chloride experiment introduction f…
A. FeCl
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most modern food production and distribution service exposes consumers …
d. All of the above
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value 3 which of the following have introduced the use of natural pest …
c. Crop cultivation ethics
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marco and his classmates are anxious about the upcoming chemistry test.…
- B. Politely refuse to cheat and start studying more. - C. Start a study group to prepare for the exam and build confidence. - E. Identify the act of cheating as wrong and too ri…
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soil permeability soil permeability is how quickly liquids can move ver…
A. It impacts irrigation and farming decisions.
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soil permeability leaching leaching can dissolve various substances lik…
C. nutrients, pesticides, and potentially harmful chemicals (assuming the options are labeled A, B, C with C being the third option as per the content)
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sample (nacl) | sample mass (g) | molar mass (g/mol) | number of moles …
The molar mass of NaCl is $\boldsymbol{58.4\ \text{g/mol}}$.
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22. what evidence best supports the presence of atmospheric oxygen 2.7 …
A. layered iron rust in rocks
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this image is a model of... a homogenous mixture a heterogeneous mixtur…
D. an element (assuming the green option is labeled D, if the labels were A: a homogeneous mixture, B: a heterogeneous mixture, C: a compound, D: an element)
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which of the following is an example of the formation of a mixture? rus…
The option with "Sugar crystals dissolving in water" (the blue - colored option with the text "Sugar crystals dissolving in water")
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question 4 (1 point) if a cosmetologist observes that a clients face ha…
c. triangular ### Question 5
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the image below is an example of a molecule an atom a homogeneous mixtu…
a homogeneous mixture
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which of the following explains why saltwater is considered a mixture? …
The option with the text "It is composed of two or more substances and retains their own chemical properties." (the yellow - colored box)
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which of the following is an example of a container filled with a pure …
A. A balloon filled with helium.
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the image below is an example of a homogeneous mixture an element a het…
a heterogeneous mixture
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which statement identifies why oxygen is classified as a pure substance…
The correct statement is the green - colored one: "Oxygen contains only one substance, but air contains several substances." (Assuming the green option is, for example, Option A, …
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three students are working with different substances to measure the che…
Chao should change the temperature, Mia should adjust the pressure, and Ezra should increase the surface area.
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when the elements copper (cu) and oxygen (o) chemically combine, they f…
a compound
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this picture is a model of a... element compound heterogeneous mixture …
heterogeneous mixture (the orange card option: heterogeneous mixture)
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the chemical equation shown below represents a reaction that produces f…
The substance classified as an element is \( \text{H}_2 \) (Hydrogen gas). If we consider the options as presented (assuming the choices are \( \text{CO}_2 \), \( \text{H}_2 \), \…
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when electricity passes through water, hydrogen and oxygen are produced…
The green - colored option (Water-- > Compound, Hydrogen-- > Element, Oxygen-- > Element)
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the chemical symbol for an element is always represented by only 1 lett…
False
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valence electrons are the electrons in the outer most energy level all …
the electrons in the outer most energy level
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the number of valence electrons ------- by 1 as you move across the per…
increases
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atomic mass equals the combined number of protons and electrons electro…
Protons and Neutrons (the orange - colored option with text "Protons and Neutrons")
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what is a motion in limine? a. a motion to dismiss the case b. the move…
c. A pretrial motion for the purpose of excluding certain evidence
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e) 9.0h + hbr3 9. mark and karen are carrying out a science project on …
When acid is added, $\ce{HCO3^-}$ reacts with added $\ce{H+}$ to form $\ce{H2CO3}$, preventing a large pH drop. The buffer equilibrium shifts left to consume excess $\ce{H+}$. ###…
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investigating chemical reactions: energy changes in substances when dif…
chemical reaction ### Question 2
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practice problems 1 the height of water in a bathtub, w, is a function …
A - 2, B - 4, C - 3, D - 1 ### Problem 2a
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akia is balancing the equation na + h₂o → naoh + h₂. he tries to find t…
by counting each individual atom and making sure the number of each kind of atom is the same in the reactants and the products
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which statement correctly describes why a compound is a pure substance?…
A compound is a pure substance because its molecule cannot be broken down into simpler particles by physical means.
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select the correct answer. which of the following is a correctly balanc…
B. $2\text{HgO} ightarrow 2\text{Hg} + \text{O}_2$
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write the correct chemical formula of polyatomic compounds covalent com…
### Part 1: Naming Covalent Compounds (Question 1) For covalent compounds, we use prefixes to indicate the number of atoms of each element. The prefixes are: 1 - mono, 2 - di, 3 -…
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part ii: lab questions 1. graph the following data on a piece of graph …
The graph is drawn by following the above steps, with properly labeled axes, appropriate scales, and two solubility curves (one for Sodium Chloride and one for Copper Sulfate) dra…
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research: real world examples research 3 examples of each change in sta…
To complete this task, we will provide 3 examples for each state change (melting, freezing, condensation, sublimation) and their explanations: ### MELTING 1. **Example 1: Candle W…
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changes in state: vocabulary matching match the word to the definition …
- GASES: No definite volume and no definite shape. - TEMPERATURE: The average kinetic energy of particles in a substance. - KINETIC ENERGY: Energy of motion. - VAPORIZATION: Liqui…
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7. elements review: fill in the chart below for some of the compounds o…
To solve this, we analyze each compound: ### Example: NaCl ## Step 1: Count Na atoms In \( \text{NaCl} \), there is 1 Na atom. ## Step 2: Count Cl atoms In \( \text{NaCl} \), ther…
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at 90°c, you dissolved 10 g of kcl in 100. g of water. is this solution…
To solve these problems, we typically refer to a solubility curve (a graph showing the solubility of various compounds in water at different temperatures). Since the specific solu…
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2) types of solutions on a solubility curve, the lines indicate the con…
First blank: saturated Second blank: below
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a flexible container holds 97.4 liters of hydrogen gas (h₂). after the …
$43.8$
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in the structure of 2,3,3 - trimethylpentane, identify the primary (p),…
- 5 terminal carbons: p - Central 4-bonded carbon: q - CH carbon (left middle): t - CH₂ carbon (right middle): s
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given six molecules, identify the molecules with polar bonds and the mo…
The molecules with polar bonds are: - $\ce{O=C=O}$ - $\ce{H2O}$ - $\ce{CCl4}$ - $\ce{CH3Cl}$
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13) what is the molarity of a solution which contains 58.5 g of sodium …
$2.00\ \text{mol/L}$ ---
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-make sure that the change of the compound equals zero. 1) $\\stackrel{…
1. $\text{Al}_2\text{O}_3$ 2. $\text{SrS}$ 3. $\text{LiCl}$ 4. $\text{CaSO}_4$ 5. $\text{K}_3\text{PO}_4$ 6. $\text{Al(NO}_3\text{)}_3$ 7. $\text{Mg(C}_2\text{H}_3\text{O}_2\text{…
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an element with mass 780 grams decays by 17.1% per minute. how much of …
16.6 grams
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loudon | parise seventh edition a unknown compound was found to have th…
- ether - alcohol
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for the first element, start with the element name. for the second elem…
B. phosphorus pentachloride
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molecular/covalent compounds naming rules - for the first element, star…
nitrogen dioxide
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why work requires force you know from experience that if work is to be …
Resistance ### 2.
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the element name. the -ide name. oms of each st element. multiple-choic…
mono-