化学
化学反応、化学量論、分子構造、元素の性質。
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multiple choice 2 points identify the marked dihedral angle in the give…
C. $0^{\circ}$
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39 multiple choice 2 points the formal charge on oxygen in dimethyl eth…
0
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t f 29 chipped or cracked glassware is okay to use. 30 read all procedu…
# Explicaciones Breves: - 29: El uso de cristalería dañada puede causar lesiones, entonces es falso. - 30: Leer cuidadosamente los procedimientos antes de entrar al laboratorio es…
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38 multiple choice 2 points provide an acceptable name for the alkane s…
3 - ethyl - 7 - methyl - 5 - propylnonane
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multiple choice 2 points which line angle drawing best represents the n…
To accurately answer this multiple - choice question, we need the specific options with labels (e.g., A, B, C, D). Since the options are not labeled, we cannot provide a specific …
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what is the mass percent of carbon in propanol, c3h8o? report your answ…
59.94% 3.51 g
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your answer may include the following changes. select each of the chang…
If considering physical changes: Heat the metal until it melts (physical change), Stretch the metal into a wire (physical change). If considering chemical changes: Attempt to reac…
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true - false t f 22 hot glass looks the same as cold glass 23 all chemi…
# Explicaciones breves: 22. El vidrio caliente y frío puede parecer similar, pero el vidrio caliente puede ser peligroso de manipular sin saberlo, aunque visualmente a simple vist…
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what is the molar mass of glucose, c6h12o6, in g/mol? answer to two dec…
Question 1: $180.18$ Question 2: $267.74$ Question 3: $11.90$
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35 multiple choice 2 points what is the major constituent of natural ga…
A. methane
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multiple choice 2 points a series of compounds, like the n - alkanes, t…
A. homologous
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multiple choice 2 points based on the structure below, what is the valu…
109°
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question 3. the diagram below shows the changes in the state of water (…
Process X is called deposition and process Y is called sublimation.
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multiple choice 2 points which of the following best describes the rela…
They represent different compounds that are constitutional isomers.
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31 multiple answer 2 points which statements about resonance are correc…
B. The true structure is a resonance hybrid, C. It involves the delocalization of electrons, D. All resonance forms must have the same number of unpaired electrons
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an industrial chemist is studying a sample of an unknown metal. describ…
- **Physical changes**: Measure density, Check malleability. - **Chemical changes**: React with acid, Expose to air for oxidation.
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multiple answer 2 points identify the functional groups in the structur…
amide: Yes, there is a -CONH - group which is an amide functional - group. aromatic hydrocarbon: Yes, there are benzene rings which are aromatic hydrocarbons. Ketone: No, there is…
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multiple choice 2 points how can you determine if two substituents on a…
C. By observing if they face the same or opposite directions on the molecule.
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question 23 (2 points) according to piaget, ________ is a concept or fr…
Question 23: C. schema Question 24: sensorimotor
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9 you are heating a piece of glass and now want to pick it up. you shou…
- 9. C. usar pinzas. - 10. C. decirle al instructor de ciencias inmediatamente. - 11. D. Todo lo anterior. - 12. D. Todo lo anterior. - 13. D. Ninguno de los anteriores.
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classify each of the following organic compounds and circle the functio…
a. Carboxylic Acid; Functional - group: $\ce{-COOH}$ (circle the $\ce{-COOH}$ part in $\ce{HCOOH}$) b. Amide; Functional - group: $\ce{-CONR_2}$ (circle the $\ce{-CON(CH_3)_2}$ pa…
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27 multiple answer 2 points which of the class of organic compound belo…
B. carboxylic acid, C. ester, D. aldehyde, E. ketone
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differentiating intensive and extensive properties the pictures to the …
Sample A melts at the same temperature as sample B. Sample B has more mass/volume than sample A. Sample A has less mass/volume than sample B. If sample A floats in water, sample B…
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26 multiple choice 2 points rank the molecules below from most to least…
A. A>C>B>D
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three - year - old henry tripped on an uneven sidewalk and ran crying t…
First question: animism Second question: Schemas
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multiple choice 2 points which of the following compounds has the highe…
The compound with two fluorine atoms (the second - option) has the highest acidity.
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question 18 (mandatory) (2 points) occurs when we incorporate new infor…
B. Assimilation/accommodation
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1. if a laboratory fire erupts, immediately a notify your instructor b …
1. A. notificar a tu instructor 2. A. notificar a tu instructor 3. D. cualquier momento en que se usen químicos, calor o cristalería 4. C. avisar a tu instructor de ciencias que l…
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2. if initially there is 38.0 mol/l of so₃(g), at equilibrium there is …
\(K_c\approx0.42\)
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79. iced tea use iced tea with and without ice cubes as examples to exp…
El té helado sin cubos de hielo es un mezclado homogéneo. El té helado con cubos de hielo es un mezclado heterogéneo. Cuando los cubos de hielo se derriten, queda un mezclado homo…
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the list below includes some of the properties of butane, a common fuel…
burns readily in air, boiling point of - 1.1°C, odorless, does not react with water
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multiple choice 2 points draw the appropriate structures and provide th…
1. Structure and IUPAC name: - Structure: A straight - chain of 7 carbon atoms (for n - heptane). IUPAC name: Heptane - Structure: A 6 - carbon chain with a methyl group on the 2n…
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23 multiple choice 2 points the synthetic steroid ru - 486 is shown bel…
10
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22 multiple choice 2 points which of the following condensed formulas c…
(CH₃)₂CC(CH₃)CO₂H
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the list below includes some of the properties of ammonia. identify the…
gas at room temperature, strong, unpleasant odor, dissolves easily in water
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multiple choice 2 points the formal charge on the nitrogen on the struc…
0
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multiple choice 2 points the formal charge on the nitrogen on the struc…
0
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multiple choice 2 points provide the name of the compound below. sec - …
D. sec - butylcyclohexane
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the list below includes some of the properties of ammonia. identify the…
gas at room temperature strong, unpleasant odor dissolves easily in water
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multiple choice 2 points how many carbons do the primary alkane constit…
A. $C_5 - C_8$
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78. seawater is composed of salt, sand, and water. is seawater a hetero…
Es una mezcla heterogénea.
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18 multiple choice 2 points shown below is one of the sex pheremones fr…
3
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calculate the mass in grams of each of the following: a) 1.38 moles of …
A. 19.33 g B. \(8.24\times 10^{9}\text{ g}\) C. \(3.19\times 10^{-8}\text{ g}\) D. \(1.20\times 10^{24}\text{ atoms}\) E. \(6.03\times 10^{23}\text{ atoms}\) F. \(3.01\times 10^{2…
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multiple choice 2 points sketch the chair conformations for the compoun…
In a cis - isomer, the two substituents are on the same side of the ring, and in a trans - isomer, the two substituents are on opposite sides of the ring. Looking at the given com…
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multiple choice 2 points what is the molecular formula for the followin…
C. $C_8H_{16}$
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multiple choice 2 points what is the name for the given cycloalkane as …
isobutylcyclohexane
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15 multiple choice 2 points what is the name for the given cycloalkane …
No correct option provided (missing structure details to determine).
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some people mistakenly believe that the element curium was discovered b…
D. nuclear chemist Glenn T. Seaborg
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arrange the following newman projections of butane in order of energy.
IV<II<III<I
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76. which of the following are the same and which are different? a. a s…
a. Son lo mismo. b. Son diferentes. c. Son diferentes. d. Son lo mismo.
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multiple choice 2 points. name the alkane shown: 5 - ethyl - 2,2 - meth…
D. 5 - ethyl - 2,2 - dimethyloctane
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11 multiple answer 2 points which statements describe a sigma (σ) bond?…
- Occurs in all single covalent bonds - It is formed by end - to - end orbital overlap - Allows free rotation around the bond axis
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10 multiple answer 2 points which statements about triple bonds are cor…
A. Are generally shorter than double bonds B. Show sp hybridization on carbon D. Consist of one sigma and two pi bonds
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multiple choice 2 points what name is given to a hydrocarbon that conta…
D. aromatic
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6. explain the difference between extensive properties and intensive pr…
6. Extensive property: mass; Intensive property: density 7. Physical change: alteration of physical form without chemical change. Examples: melting ice, cutting paper 8. Solids: p…
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multiple choice 2 points which of the following has the highest boiling…
The compound with the -OH group (the third - option with the OH functional - group)
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the lewis structure of pentane is shown below. which of the following r…
D. $CH_3(CH_2)_3CH_3$
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multiple choice 2 points which line - angle formula corresponds to the …
IV
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determine which compound for the group below will be the least soluble …
C. Chlorocyclopentane will have the lowest solubility in water because it is the least polar of the three compounds.
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multiple choice 2 points which of the following condensed formulas repr…
CH₃CH₂CH₂OCH₂N(CH₂CH₂CH₃)₂
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determine which structure(s) correspond to a cis isomer.
In cis - isomers, identical groups are on the same side of the ring. Analyzing the given structures: - In structure (i), the two $NH_2$ groups are on the same - side of the ring, …
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provide the planar form of the chair conformation below. 54:40 time rem…
Without seeing the specific correct option among the ones provided in the image (as the image quality may not allow for clear identification of details), the general approach is t…
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75. “a mixture is the chemical bonding of two or more substances in any…
# Explicación breve: Una mezcla se forma por la simple combinación física de dos o más sustancias, sin que se produzca un enlace químico entre ellas. Las sustancias en una mezcla …
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1. what is the definition of chemistry? the study of the composition, s…
1. Chemistry is the study of the composition, structure, and properties of matter. 2. Organic, Inorganic, Physical, Analytical, Biochemistry, Theoretical. 3. Basic research is for…
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60. is it possible to distinguish between an element and a compound? ex…
# Explicaciones Breves: Un elemento está formado por un solo tipo de átomo y no puede descomponerse en sustancias más simples por métodos químicos normales. Un compuesto está form…
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14. which statement concerning ⁷⁹₃₄ se and ⁷⁹₃₅ br is true? a. ⁷⁹₃₄ se …
B. $^{79}_{34}Se$ has more neutrons per atom than $^{79}_{35}Br$.
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match each of the following as a physical or chemical change. answers w…
milk turns sour: Chemical change butter solidifies: Physical change wood is burned: Chemical change food is digested: Chemical change coffee beans are ground: Physical change ice …
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56. state the definition of element. 57. correct the following statemen…
56. Un elemento es una sustancia pura formada por un solo tipo de átomo que no puede ser descompuesta en sustancias más simples por medios químicos normales. 57.a. Un elemento es …
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graded formative: unit 1 study guide part 1 classify each substance bel…
Propanol (C₃H₇OH): compound Xenon (Xe): element Kool-Aid drink solution: homogeneous mixture oil & vinegar: heterogeneous mixture
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57. correct the following statements. a. an element is a combination of…
a. Un elemento es la forma más simple de materia que no puede descomponerse en otras sustancias químicas más simples por métodos químicos comunes. b. Cuando un pequeño monto de az…
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format and style quick check \why shade balls may not save water\ by am…
by inserting a heading about the topic of the second section
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whats the difference between an acid and a base?
Acids release hydrogen ions in solution, taste sour, and react with bases. Bases release hydroxide ions or accept hydrogen ions, taste bitter, feel slippery, and have different in…
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graded formative: unit 1 study guide part 1 jane calculated the density…
accurate and precise
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31. list three examples of substances. explain why each is a substance.
1. Agua (H₂O): Compuesto formado por oxígeno e hidrógeno en proporción fija. 2. Oxígeno (O₂): Elemento, átomos de oxígeno, no descomponible químicamente. 3. Hierro (Fe): Elemento,…
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question 2. during a chemical reaction, if 25 grams of reactants are co…
The law of conservation of mass is upheld because the mass of the products equals the mass of the reactants.
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approximately how many elements are there in the modern table? a 20 b 5…
C. 100
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who invented the periodic table? a albert einstein b august kekulé c ch…
D. Dmitri Mendeleev
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question 1. a pure white, solid material that looks like table salt rel…
A chemical change occurred because the material released gas when heated, which indicates a change in its chemical reactivity and composition.
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which statement best describes the arrangement of electrons in an atom …
There are two electrons in the first energy level and seven electrons in the second energy level.
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which element has atoms with valence electrons in a higher energy level…
A. Strontium (Sr)
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helium is in group 18 of the periodic table. how is helium different fr…
Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.
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two representative elements, nitrogen and oxygen, are in the same perio…
They have valence electrons in the same energy level.
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how many valence electrons does each atom of arsenic (as) have? arsenic…
5
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q8. how many liters of a 25% sulfuric acid solution should be mixed wit…
5
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calculate the volume of a solvent from a solution that has a density of…
$0.206$ L
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instructions: using the diagram below as a reference, fill in the missi…
The above diagram shows what happens as heat is applied to a substance. Beginning at point A on the timeline, the material is a solid and has a definite volume and a definite **sh…
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assignment #4 quiz (a4 - 1 point) why does oil not dissolve in water? w…
Water is polar and oil is nonpolar so hydrogen bonds cannot form between water and oil.
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assignment #4 quiz (a4 - 1 point) water is a molecule because the oxyge…
Polar
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(a4 - 2 points) drag and drop the correct answer in each box to complet…
1. Acids 2. Bases
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1 - 5 density the concept of density is about how close atoms and molec…
1. 9; 9 2. 2 3. 1 4. 2 5. mass 6. volume
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what is matter? mention one example of matter and say if you think is p…
Matter is anything that occupies space and has mass. An example of matter is water. Pure water consists only of H₂O molecules. But natural - water like river water is not pure as …
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6. the author uses the statement \these technological marvels seem like…
6. G. consumers regard many technological inventions as unremarkable. 7. D. our current pattern of lifestyles and consumer habits.
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a 52 - kg woman has 7.2×10⁻³ mol of hemoglobin (molar mass = 64456 g/mo…
$4.3\times 10^{41}$ molecules of hemoglobin (rounded to 2 significant - figures as 7.2 has 2 significant - figures)
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1 st alice tente didentifier un sucre inconnu qui est soluble dans leau…
#### a) On a calculé que la concentration du sucre inconnu en solution saturée est inférieure à ce que devrait être la solubilité du saccharose à $22^{\circ}C$ en utilisant le gra…
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lesson 2.2 review 1. what does it mean when a molecule is said to be “p…
1. Uneven charge distribution. 2. It's polar and forms hydrogen - bonds. 3. A substance resisting pH change; maintains cellular pH.
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5. describe two observations of water that provide evidence that water …
1. Water forms droplets. 2. Water has high surface - tension (e.g., insects can walk on it).
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reading check (page 48) how are cohesion and adhesion similar? how are …
Similarity: Both are intermolecular attractions. Difference: Cohesion is like - molecule, adhesion is unlike - molecule. Solvent in tea: Water. Solute in tea: Tea compounds.
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reading check (page 45): how are ionic and covalent bonds alike? how ar…
1. Protons and neutrons in nucleus, electrons in energy - levels around it. Diagram with labeled parts. 2. Same number of protons means same electron configuration and chemical be…
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lesson 2.4 review 1. what changes occur to chemical bonds during a chem…
1. Chemical bonds break and new ones form. 2. Exergonic (negative - energy change) reactions are likely to occur. 3. Enzymes catalyze reactions in living things by lowering activa…
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4. osha was created as part of the u.s. department of labor (dol) to en…
5. To ensure that employers and employees understand the physical and health hazards of chemicals in the workplace. 6. They protect my health by making me aware of and able to man…