化学
化学反应、化学计量、分子结构与元素性质。
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chemistry 20: bonding unit. molecular shapes. choose model\ molecule sh…
### For $\ce{NH_{3}}$: #### Lewis Dot Diagram: - Nitrogen ($\ce{N}$) has 5 valence electrons, and each hydrogen ($\ce{H}$) has 1. - $\ce{N}$ forms 3 single bonds with 3 $\ce{H}$ a…
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2. draw a diagram of a correct bunsen burner flame and label the hottes…
The Bunsen burner flame (with open air hole) has an inner blue cone (unburnt gas - air mixture) and an outer cone (complete combustion). The hottest spot is at the tip of the inne…
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iron has a density of 7.86 g/cm³. calculate the volume (in dl) of a pie…
\(4.31\)
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looking for patterns in household objects/chemicals object/chemical | o…
To solve the task of identifying patterns and listing observations, we analyze each object/chemical: ### Step 1: Recall Definitions - **Element**: Pure substance with one type of …
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decide whether each pair of elements in the table below will form an io…
To solve this, we analyze each pair of elements: ### 1. Oxygen (O) and Chlorine (Cl) - **Step 1: Check Ionic Compound Formation** Ionic compounds form between metals and nonmetals…
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how does solid rock become soil? it falls apart and combines with parti…
The correct option is: It breaks down and combines with water, air, and organic matter.
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which type of weathering is caused by plants? ○ chemical weathering ○ m…
both mechanical and chemical weathering
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1 kg / 1000 g 1000 mg / 1 g 1 mg / 1000 µg 1000 µg / 1 mg 1000 g / 1 kg…
### Part A (Filling the Conversion Factor Table) #### 1. 500 g of medication A in terms of mg ## Step1: Identify the conversion factor We know that to convert grams (g) to milligr…
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which factor influences both chemical weathering and mechanical weather…
plants
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17. why is water such a good solvent?
Water is a polar molecule with a partial positive charge on hydrogen and partial negative on oxygen, can form hydrogen bonds, and its polarity/intermolecular forces interact with …
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15. in a cup of tea, what is the solvent? what is the solute?
- Solvent: Water (the liquid in the tea that dissolves other substances). - Solute: Compounds from tea leaves (and any added substances like sugar, etc.) that are dissolved in wat…
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this passage describes a chemical reaction. read the passage. then, fol…
product
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sls: materials use the information below to answer the question. when d…
A. alumide
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select the correct answer from each drop - down menu. what causes atoms…
First drop - down: each atom and the shared electrons Second drop - down: the valence electrons of the two atoms
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ammonia is commonly used as a fertilizer for plants. it is made when ni…
- Number of H atoms: \( 24 \) - Number of N atoms: \( 8 \) - Molecules of \( NH_3 \): \( 8 \)
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this passage describes a chemical reaction. read the passage. then, ans…
- sodium (Na) (selected) - nitrogen ($N_2$) (selected) - sodium azide ($NaN_3$) (unselected)
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4) use the mass spectrum below to fill out the information in the table…
To solve this, we analyze the mass spectrum and use atomic structure knowledge (protons = atomic number, neutrons = mass number - protons, mass from spectrum, abundance from relat…
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elija tres pasos que garanticen la seguridad del laboratorio durante el…
- Usando pinzas para manipular los tubos de ensayo calientes - Apagar la placa calefactora después de usarla - Comprobación de que el vaso de precipitados no tenga virutas antes d…
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laboratorio: identificación de nutrientes asegúrese de obtener medicion…
A (the pipette labeled A)
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which is the best definition of activation energy? the energy required …
the energy required to form or break the bonds of reactant molecules
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a researcher is designing a laboratory experiment to determine whether …
B. First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A t…
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which of the following is the quantity of diluent a pharmacy technician…
245 mL
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eastern woodlands – the lenape of new jersey the lenape, also known as …
- Way 1: The Lenape located their villages along rivers (e.g., Delaware, Passaic, Raritan) which served as trade corridors and food sources, adapting to the water - rich New Jerse…
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where is water found on the ph scale? ○ 4
7 (Note: If the question expects choosing from the given option “4” and other unshown options, but based on chemistry, pure water has a pH of 7. If “4” is the only shown option an…
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how many neutrons are found in a carbon atom?
6
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express your answer with the appropriate number of significant figures.…
60.0 mL
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correct correct answer is shown. your answer 78.0 ml was either rounded…
\(62.0\)
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the atoms in o=c=o (carbon dioxide) are held together by this type of b…
D. non - polar covalent
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3. station 3: demo- baking soda and vinegar in a cup go to the demo sta…
s (Filled Table - Example) | Question | Answer | |-----------------------------------|-----------------------------------------------------------------------| | What is the initia…
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bell ringer chormatography what is the stationary phase in paper chroma…
C. The paper
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bell ringer chormatography paper (stationary phase) ink spot to be sepa…
The red dye is attracted to the mobile phase
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2. what trends do you notice for the atomic radii of group 2a? 3. what …
As atomic number increases (moving down Group 2A), atomic radii increase. ### Question 3
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2.27 × 2.2 = ? 2.27/2.2 = ? 2.27 + 2.2 = ? 2.27 − 2.2 = ? incorrect rou…
To solve these problems, we'll apply significant figure rules for each operation (multiplication/division, addition/subtraction). ### 1. \( 2.27 \times 2.2 = ? \) #### Step 1: Per…
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summary questions 1. what is an atom? a) the smallest part of an elemen…
a) The smallest part of an element that retains the properties of that element. ### Question 2
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6. on the same graph, make a line graph the first three atoms in group …
To create the line graph: 1. **Plot Points**: Mark (4, 900) for Be, (12, 736) for Mg, and (20, 590) for Ca on the graph (x - atomic number, y - ionization energy). 2. **Draw Line*…
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2. what trends do you notice for the atomic radii of group 2a? 3. what …
As we move down Group 2A (from top to bottom), the atomic radii **increase**. This is because each successive element has an additional electron shell, increasing the distance bet…
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question: shining x-ray light on a crystal molecule to determine its th…
x - ray crystallography.
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camera, the photographer has 28 nominal minutes to develop it, using mo…
D) mere ### Question 29
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within a period: electronegativity increases from (left to right, right…
### Part 1: Electronegativity Trends #### Within a Period: Electronegativity increases from **LEFT to RIGHT** because atoms on the right need **LESS** electrons to complete their …
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camera, the photographer has ██ nominal minutes to develop it, using mo…
D) mere ### Question 29
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wet plate photographers essentially create their own film. the process …
B) Yes, because it sets up the paragraph’s outline of the process of wet plate photography. ### Question 26
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wet plate photographers essentially create their own film. the process …
C) No, because it blurs the paragraph’s focus on the dangers involved in wet plate photography. ### Question 26
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ii. electronegativity- is ability of an atom to _______________ to itse…
### Part II: Electronegativity Definition Electronegativity is the ability of an atom to **attract electrons** to itself to become **stable** (by **gaining** electrons). ### 1a: O…
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24. hydrogen bonds are a form of ________ interaction, where ________ b…
intermolecular, hydrogen, electronegative, electronegative, molecule
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24. hydrogen bonds are a form of __________ interaction, where ________…
intermolecular; hydrogen; electronegative; electronegative; molecule
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2. a. calculate the atomic mass in amu or u of unknown element with the…
(Part a): The atomic mass of the unknown element is approximately \(\boldsymbol{39.95}\) amu (or u). ### Part b: Identify the Element
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drag the appropriate labels to their respective targets. view available…
# Explanation: ## Step1: Round 12.462 to different sig figs - Four sig figs: 12.46 (wait, no, 12.462 has digits 1,2,4,6,2. Four sig figs: look at the fifth digit (2) to round the …
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carbon • carbon has the ability to create ______ bonds with up to _____…
- carbon has the ability to create \(\boldsymbol{\text{covalent}}\) bonds with up to \(\boldsymbol{4}\) other \(\boldsymbol{\text{atoms}}\) - covalent bonds are very \(\boldsymbol…
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marie curie discovered elements radium and polonium. is this an example…
A. Science
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instructions: classify each of the following as an intensive property i…
E ### 42. Density Density (\( ho = \frac{\text{mass}}{\text{volume}} \)) is intrinsic (same for any amount of the substance). So, it is an intensive property.
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6. state the number of significant digits in each of the following meas…
6. (a) 3 (b) 2 (c) 3 (d) 1 (e) 3 (f) 2 (g) 3 (h) 1 7. (a) 60.76 g (rounded to 60.76? Wait, 50.511 + 10.25 = 60.761, and the least decimal places is 2 (from 10.25), so round to two…
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(\frac{16.83}{15} - 0.46) nd the answer appropriately s your answer num…
0.66 (or 0.662, depending on sig fig interpretation. But likely 0.66 when rounded to two decimal places)
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evaluate: $\frac{4.00}{10} = 0.40$ and round the answer appropriately e…
0.4
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instructions: classify each of the following changes in matter as physi…
To solve this, we determine if a change is physical (no new substance, just state/shape) or chemical (new substance formed). ### 31. Grinding chalk into powder - Explanation: Only…
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14.2 four special kinds of pronouns (demonstrative and relative pronoun…
### Exercise 1: Recognizing Demonstrative Pronouns (Underline the demonstrative pronouns) 1. **Step 1: Identify demonstrative pronouns (those, these, that, this).** - Sentence: *T…
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write 13.3 kilocalories using the unit abbreviation.
$13.3$ kcal
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instructions: classify each of the following properties of matter as ph…
P ### 22. Density Density is a physical property (measured without chemical change).
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instructions: classify each of the following as an elemente, a compound…
E ### 12. Water Water ($\ce{H_2O}$) has hydrogen and oxygen atoms bonded.
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name josiah pollock 9/10/25 chemistry i worksheet classification of mat…
s: 1. E 2. O 3. O 4. E 5. O 6. E 7. E 8. O 9. O 10. O
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reading the periodic table of elements: use the periodic table above to…
### Question 1: Write the SYMBOL for each of the following elements #### a. Carbon Carbon's chemical symbol is a well - known symbol in chemistry. The symbol for carbon is $\text{…
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evaluate (6 \times 0.222 \times 7.0) and round the answer appropriately…
\(9\)
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name ______ chemistry i worksheet classification of matter and changes …
### Part 1: Classify as Heterogeneous (E) or Homogeneous (O) 1. **Wood**: It has different components (e.g., fibers, lignin) not uniformly distributed. So, E. 2. **Freshly - brewe…
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1. define atom: 2. what does the greek word atomos mean? 3. what three …
indivisible ### Question 3
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date ______ name ______ section ______ postlaboratory assignment 1. sta…
meter #### (b)
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an atom with a positive or negative net charge is called an ion. select…
The top - left and top - right atomic models (the ones with a net charge, i.e., unequal number of protons and electrons). If we consider the visual check - marks, the top - left (…
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some atoms have an unequal number of protons and electrons, which gives…
The number of protons in the lithium atom is \(\boldsymbol{\text{equal to}}\) (wait, no, 3≠2) wait, no, I think I messed up. Wait, maybe the diagram has 3 protons and 3 electrons.…
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this model represents a lithium ion. image of lithium ion with legend: …
The lithium ion is \(\boldsymbol{\text{positively}}\) charged. The ion would attract a \(\boldsymbol{\text{negatively}}\) charged ion and would repel a \(\boldsymbol{\text{positiv…
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an atom can become an ion by losing electrons to or gaining electrons f…
Sodium \(\boldsymbol{\text{loses}}\) an electron, and chlorine \(\boldsymbol{\text{gains}}\) an electron. So sodium becomes \(\boldsymbol{\text{positively}}\) charged, and chlorin…
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an atom with a positive or negative net charge is called an ion. select…
The models of ions are the top - left, top - right (if protons ≠ electrons), and bottom - left. However, based on the standard definition and typical ion diagrams, the correct mod…
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practice: 1. describe the uses of the following safety equipment: eye w…
- Eye wash: Flush eyes with contaminants. - Chemical/safety shower: Rinse body with hazardous chemicals. - Fire blanket: Smother small fires/cover burning person. - Fire extinguis…
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part c : identify & draw b) label the pictures with the words. remember…
### Respuesta y Explicación para la Imagen 1: # Breves Explicaciones: La imagen 1 muestra varias moléculas idénticas, cada una formada por dos átomos del mismo tipo (ya que los át…
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chemical manufacturers must present which information on the product’s …
D. All of the above (assuming the options are labeled A - D with D as "All of the above"; if original options have "All of the above" as the last option, the answer is that option…
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an atom with a positive or negative net charge is called an ion. select…
All four models (top - left, top - right, bottom - left, bottom - right) are models of ions. If we assume the options are labeled (e.g., A: top - left, B: top - right, C: bottom -…
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the diagram below shows atoms that are all arranged into groups in the …
C. a single type of substance
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directions: select all the correct answers. which of the following stat…
A. Atoms may be joined together in well - defined molecules. B. Atoms may be arranged in repeating crystal patterns. C. All ordinary substances are made of atoms.
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practice: 1. describe the uses of the following safety equipment: eye w…
- Eye wash: Flush eyes after chemical exposure. - Chemical/safety shower: Rinse body after chemical splash. - Fire blanket: Smother small fires (e.g., clothing, small lab fires). …
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7 donne la formule chimique la plus probable des ions formés par les él…
D. Les ions sont des atomes qui portent une charge électrique.
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diamond and graphite contain only carbon atoms, yet they are very diffe…
A. Their atoms are arranged differently.
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answer the questions with element (e), compound (c), or mixture (m). 1.…
E ### 2. You can see the different parts. Mixtures (especially heterogeneous ones) have visibly distinct parts (e.g., salad, sand and water).
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the image below is a 3-d model of ammonia (nh₃). what term best describ…
D. molecule
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directions: select the correct image. which picture best represents a s…
The fourth image (with red, blue, red spheres connected)
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how is a compound different from an element at the microscopic level? a…
B) A compound is made of atoms chemically bonded from different elements.
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calcite is mineral that is found in limestone and marble. a model of th…
B. It is formed by a repeating pattern of different types of atoms.
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do you ever wonder how batteries create enough power to light a flashli…
To solve the fill - in - the - blanks for the battery - building steps, we analyze the context: ### Step 1: First blank (put a _ down) The experiment is about building a battery w…
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scientists use different types of models to study the composition of ma…
1. "shows how several water molecules are oriented in space relative to one another in addition to showing relative size and number of atoms in a molecule" → "particle model for w…
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aluminum foil what you do first, cut the cardboard into 7 squares that …
The first step is to put a \(\boldsymbol{\text{penny}}\) down. Next, you place a \(\boldsymbol{\text{cardboard}}\) square. To finish the first cell, put a \(\boldsymbol{\text{nick…
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which will decrease the kinetic energy (energy of motion) of water mole…
D. Place the water in the freezer
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acetylene gas is not explosive. true false 8 of 25
B. False
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understand technical texts — quiz — level c do you ever wonder how batt…
battery
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directions: select each correct answer. more than one answer may be cor…
- many elements - a single element
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11 explain what makes a water molecule polar 12 match the property of w…
A water molecule is polar because oxygen is more electronegative than hydrogen, creating partial charges ($\delta^-$ on O, $\delta^+$ on Hs), and its bent shape means dipole momen…
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old pennies become dull when the copper on the outside combines with ox…
iron
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a picture of a ______ is the label pictogram on a chemical that warns o…
A. Skull and crossbones
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old pennies become dull when the copper on the outside combines with ox…
First blank: shiny; Second blank: iron
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old pennies become dull when the copper on the outside combines with ox…
clip
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ammonia is commonly used in cleaning solutions, as well as in manufactu…
D. Ammonia is composed of molecules that can freely move past each other.
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old pennies become dull when the copper on the outside combines with ox…
into
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finally, rinse off the paper clips with water. place them on a paper to…
chemical
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while the pennies are drying, put the paper clips in the bowl of soluti…
A. Add the paper clips to the bowl.
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which step comes after removing the pennies from the solution? e the pe…
A. Add the paper clips to the bowl.