Chimie
Réactions chimiques, stœchiométrie, structures moléculaires et propriétés.
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collection 2: create the multiple molecules indicated below chemical fo…
### For 2 carbon dioxide ($\boldsymbol{2CO_2}$): # Explanation: ## Step1: Determine Chemical Formula The formula for carbon dioxide is $CO_2$, so 2 molecules is $2CO_2$. ## Step2:…
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which of the following contains the highest number of atoms? 1 mole of …
All contains an equal number of atoms.
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the atomic mass of nitrogen (n) on the periodic table is 14.00677 amu. …
A. The presence of different isotopes
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question 1 / 1 what is the sodium ions charge? it has 11 protons. it ha…
A. +1
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collection 1: create each molecule and complete the chart chemical form…
### For \( \boldsymbol{O_2} \): # Explanation: ## Step1: Name the molecule \( O_2 \) is a diatomic molecule of oxygen, so its name is Oxygen (or Diatomic Oxygen). ## Step2: Count …
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which of the following best describes the difference between molar mass…
B. A formula weight is the mass of one molecule or formula unit while a molar mass is the mass of one mole of molecules or formula units.
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avogadros number is a constant that helps scientists count atoms and mo…
D. \(6.02\times10^{23}\)
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question 1 1 p what is one atomic mass unit? ○ it is 12 mass of carbon …
B. It is 1/12 mass of one carbon atom
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which products are formed during the decomposition of magnesium nitride…
D. $3\ce{Mg} + \ce{N_2}$
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type the correct answer in each box. balance the chemical equation. □ n…
2, 2, 3 (in the order of \( \ce{N2O3} \), \( \ce{N2} \), \( \ce{O2} \) coefficients)
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there are some sections of the sds that are not mandatory. 2 of 25 true…
True
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which phrase describes a polymer? a. a branching structure containing 1…
C. a long chain of carbon atoms with hydrogen atoms attached to them
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classwork: stick and ball models instructions in this assignment you wi…
To solve this, we use the information that the number of holes in the ball (atom model) represents the number of chemical bonds the atom can form. So we directly take the number o…
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24 select the correct answer. which element is the most reactive nonmet…
D. fluorine (F)
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select the correct answer. which element is the most reactive nonmetal?…
D. fluorine (F)
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stick and ball: build a molecule! first and last name: 1. 2. 3. date: p…
Number of elements: 3; Names: Carbon, Hydrogen, Oxygen ### Part b)
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copper carbonate (cuco₃) reacts with hydrochloric acid (hcl) according …
D. Exactly one reactant is a solid, and exactly one product is a gas.
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did an oxidation-reduction reaction occur in the reaction between coppe…
D. This is not a redox reaction because no electrons were transferred.
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drag the tiles to the correct location on the table. not all tiles will…
| Alkali Metals | Halogens | |----|----| | are placed in group 1, can be cut with a knife | are placed in group 17, react vigorously with metals |
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how does adding oxygen (o₂) to this reaction change the equilibrium? 2s…
A. The equilibrium shifts right to produce more \( \text{SO}_3 \) molecules.
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a student hears in chemistry class that a certain object is made of a p…
D. It is made of either an element or a compound.
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the electron dot diagram for an unknown element x is shown. what elemen…
C. phosphorus
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identifying characteristics of atoms 20 20 a b c 9 d e 19 f using the p…
- A: 20 - B: 39 - E: 9 (Note: These values are derived from atomic structure relationships: Mass Number = Atomic Number + Neutrons, and Atomic Number = Protons = Electrons in neut…
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what is the noble gas electron configuration of bismuth (bi)? a. kr 6s²…
C. \([Xe] 4f^{14} 5d^{10} 6s^{2} 6p^{3}\)
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select the correct answer. in an experiment, chemists heated a solid, r…
C. The experiment shows that the red substance experienced a chemical change.
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what is the chemical name of the covalent compound $p_4s_3$? a. tetraph…
C. tetraphosphorus trisulfide
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a student has samples of five different types of metal. she measures th…
E. silver 10.49
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which statement correctly describes metallic bonds? a. they form when c…
E. They form because electrons can move freely between atoms.
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select all the correct answers. which statements about the structure of…
B. The inner transition elements are placed at the bottom of the periodic table for easy viewing. D. The distribution of electrons in energy levels is responsible for the shape of…
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in which reaction is precipitation occurring? a. mgcl₂(aq) + cuso₄(aq) …
B. \( \text{CdSO}_4(\text{aq}) + \text{K}_2\text{S}(\text{aq}) ightarrow \text{CdS}(\text{s}) + \text{K}_2\text{SO}_4(\text{aq}) \)
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select the correct answer from each drop-down menu. identify the type o…
Equation A represents a synthesis reaction, and equation B represents a combustion reaction.
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select the correct answer. which element or compound has lost electrons…
C. Li
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select the correct answer. the half reaction of an oxidation-reduction …
C. It is reduced.
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what inference can be drawn from the graph? a + b \ ightleftharpoons c …
A. The reaction between A and B is reactant favored.
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how would adding the catalyst nitrogen monoxide (no) affect this reacti…
A. NO increases the rate at which \(SO_3\) molecules are formed.
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which of the following observations best demonstrates water’s special p…
C. Water forms droplets of dew on a spider web in the morning
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drag each label to the correct location on the image. label each half c…
- Left electrode (Zn electrode): anode; Left process: oxidation - Right electrode (Cu electrode): cathode; Right process: reduction So the labels should be: - Left electrode box: …
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drag each label to the correct location on the image. label each half c…
- Left "electrode" box: anode - Left "process" box: oxidation - Right "electrode" box: cathode - Right "process" box: reduction
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drag each label to the correct location on the image. label each half c…
- Left electrode (Zn) label: anode - Left process label: oxidation - Right electrode (Cu) label: cathode - Right process label: reduction
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which equations represent precipitation reactions? □ na₂s + febr₂ → 2na…
The equations that represent precipitation reactions are: - \(Na_{2}S + FeBr_{2}\to2NaBr + FeS\) - \(MgSO_{4}+CaCl_{2}\to MgCl_{2}+CaSO_{4}\) - \(AgNO_{3}+NaCl\to AgCl + NaNO_{3}\)
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select the correct answer. a substance is followed by the symbol (l) in…
B. The substance is in the liquid state.
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select the correct answer. which substance in this redox reaction is th…
B. \( \text{AgNO}_3 \)
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9. i am allowed to ________ chemicals in the lab. a. taste b. touch c. …
9. C. Waft 10. B. Unsafe 11. B. Unsafe 12. E. Our classroom contains all of the safety equipment listed above 13. A. Safe 14. B. Unsafe 15. Hazards identification and first aid me…
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question 13 (10 points) match the following correctly. column a 1. _d_ …
3. e. into the proper waste collection container
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classify the reactions as endothermic or exothermic. the reaction betwe…
To solve this, we recall: - **Endothermic Reaction**: Absorbs heat (surroundings feel cold). - **Exothermic Reaction**: Releases heat (surroundings feel hot). ### Step 1: Identify…
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the diagram shows hydrogen bonds between water molecules. label the dia…
- Large blue sphere: O - Small light - blue spheres: H - Sphere with partial positive charge: $\text{H}^+$ (or $\delta^+$) - Hydrogen bond between $\text{H}^+$ (of H) and O (of an…
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a student measured the maximum mass of salt that can dissolve in 100 ml…
the temperature of water
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do now: copy and complete in your notebook the sugar used in coffee is …
- Number of elements in sucrose: \( \boldsymbol{3} \) - Name of elements: Carbon, Hydrogen, Oxygen - Number of atoms in a sucrose molecule: \( \boldsymbol{45} \) - Explanation: Ad…
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amanda and pal were in science lab, trying to identify a colorless liqu…
### First blank (Amanda's observation - curved water edges): - **Explanation**: The upward curving of water edges in a test tube is due to adhesion (attraction between water and t…
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solubility rules 1. compounds containing group 1 alkali metals or ammon…
E. \(BaSO_{4}\)
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in this reaction, how does the rate of forward reaction vary with the c…
C. It increases with a decrease in the concentration of \(H_2(g)\), D. It decreases with an increase in the concentration of \(S_2(g)\), E. It decreases with increase in the conce…
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1. after completing an experiment, all chemical wastes should be ______…
1. B. Disposed of according to your teacher's directions 2. A. Always against the rules 3. A. True 4. B. To wash chemicals out of a person's eyes 5. Typically mounted on the wall …
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type the correct answer in each box. which chemical symbols will comple…
The first box is \( \text{Na} \), the second box is \( \text{Cl} \), and the third box is \( \text{Br} \). So the completed equation is \( 2\text{NaBr} + \text{Cl}_2 ightarrow 2\b…
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step 1: determine how many ______ electrons you have in total. total va…
valence (the checkbox next to "valence" should be selected)
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which statement, a, b, or c is accurate? use the table of reduction pot…
B. Hydrogen is a very good energy source for those that can use it.
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which of the following pairs of atoms would you expect to combine chemi…
To determine which pairs form an ionic compound, we use the rule that ionic compounds are typically formed between a metal and a non - metal (or a polyatomic ion). Let's analyze e…
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what kind of bond is it when an electron is fully transferred to anothe…
Ionic (the option corresponding to "Ionic" should be selected)
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from \moon’s south pole is full of mystery, science, intrigue 1 nasa ha…
2. a sense of excitement
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which of the following pairs of atoms would you expect to combine chemi…
a. Li and S, c. Al and O, e. I and K ### Part 2: Electrons to Lose for Noble Gas Configuration #### Sub - question a: Ca
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generally speaking* atoms want to have a full valence shell (8 electron…
stable (the checkbox next to "stable" should be selected)
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select the atom which does not require 8 electrons in its outermost she…
Helium
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question 8 (6 points) which is the correct conversion factor for conver…
c. \(\frac{1\,\text{g}}{10\,\text{dg}}\)
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multiple-choice question only after the discovery of ______ in the 1890…
electrons (the option corresponding to electrons, assuming the last option is electrons with a typo as "electrong" which should be "electrons")
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4. describe two ways that an ion forms from an atom. 5. explain why ion…
1. An atom can form a cation (positive ion) by losing one or more valence electrons (e.g., $\text{Na} \to \text{Na}^+ + e^-$). 2. An atom can form an anion (negative ion) by gaini…
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what really causes atoms to stick together, forming chemical bonds is a…
Electrons (the option with "Electrons" should be selected)
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part iii – the phosphorus cycle 5. pick one step in the phosphorus cycl…
Step chosen: Weathering of Rocks. Real - world example: In a mountainous granite - rich region, rainwater with dissolved $CO_2$ (forming carbonic acid) weathers phosphorus - conta…
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question 6 (5 points) determine the correct number of significant figur…
To solve for the number of significant figures in each value, we use the rules of significant figures: - Non - zero digits are always significant. - Zeros between non - zero digit…
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name ______ class ____ date ____ after reading lesson 1.3, answer the f…
s: 1. The pursuit of transforming base metals into gold and the search for the elixir of life (or similar descriptions of alchemical goals like making medicinal potions, etc.). 2.…
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after reading lesson 1.3, answer the following questions. an experiment…
c. oxygen
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f | 1.3 | elements and principles of digital design 2 of 4 match the la…
Proximity - The principle of design which states that elements near each other are perceived as related, while elements spaced apart are perceived as belonging to separate groups.…
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1. identify each property below as more typical of a metal or a nonmeta…
nonmetal #### Part b
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atomic structure - show what you know select all statements that are tr…
- The number of protons give the atom its identity - They have a mass of 1 amu - They are located in the nucleus
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atomic structure - show what you know which of the following statements…
The incorrect statement is: They have a charge of +1.
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atomic structure - show what you know which of the following statements…
D. They are negatively charged and dictate chemical properties (assuming the last option is D; if options are labeled differently, adjust the label but the statement is "They are …
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how does a catalyst work? ○ by increasing the temperature of a chemical…
D. by decreasing the activation energy of a reaction
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choose which type of weathering each process is demonstrating (4 points…
s (matching each process to its weathering type): - Frost Wedging: physical weathering - Carbonation: chemical weathering - Oxidation: chemical weathering - Exfoliation: physical …
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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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choose the statement that correctly compares physical weathering and ch…
C. Chemical weathering forms new substances while physical weathering does not.
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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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if you want to protect your family from the rash of diseases caused by …
2. to play upon the fears of potential customers and inspire them to see the product as a solution
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question 3 of 10 which sentence is an example of an inciting incident i…
B. Danny is visited by Chin - Kee.
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directions: for the following statements,match the words with the defin…
Organic chemistry ### Part h
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discovering the nucleus: in ______ model of the atom, electrons travel …
### Discovering the Nucleus: In the **Rutherford (or planetary)** model of the atom, electrons travel around the nucleus like planets around the sun. Rutherford experimented using…
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atomic theory part 2- isotopes quick review on early atomic theory: an …
s (filling the blanks in order): 1. atom 2. Dalton 3. divisible 4. subatomic 5. Thomson 6. electrons 7. Cathode 8. positively 9. electrons 10. Rutherford's 11. gold foil
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thomson concluded from his research that the mass of the negative charg…
- First blank (Thomson's model): plum - pudding - Second blank (model with electrons around nucleus): Rutherford's - Third blank (Rutherford's experiment material): gold foil
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atomic theory part 2- isotopes quick review on early atomic theory: an …
s: 1. atom 2. Dalton 3. not indivisible 4. subatomic 5. Thomson; electrons 6. Cathode; positively; electrons 7. Rutherford; gold foil
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which story premise most clearly lacks conflict? a. a chemistry teacher…
B. A man and a woman ride the same bus to and from work every day but never speak to each other.
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atomic theory part 2- isotopes check for understanding: how many neutro…
20 ### Review Questions: 1. **Question 1**
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atomic theory part 2- isotopes quick review on early atomic theory: an …
### Quick review on Early Atomic Theory: An **atom** is the smallest particle of an element that retains its identity in a chemical reaction. The existence of atoms as indivisible…
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in the poems, how does shakespeare allude to, or refer to, ovid’s poem?…
C. by personifying time as cruel and destructive
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3. which conclusion was a direct result of the gold foil experiment? an…
The correct option is: An atom is mostly empty space with a dense, positively charged nucleus. (The option with the radio button next to "An atom is mostly empty space with a dens…
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3. in what type of reaction do the products of the reaction always poss…
A. Endothermic
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use the periodic table to answer the question which statement best desc…
There are two electrons in the first energy level and seven electrons in the second energy level (the first option among the given choices).
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3. which process is exothermic? options: - boiling of water - melting o…
Condensation of ethanol vapor
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10 when should safety goggles be worn in a laboratory? (1 point) when h…
D. for all experiments (assuming the options are labeled A - D in order, with "for all experiments" being the last option)
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reactions with a positive change in enthalpy -- are exothermic because …
The correct option is: "are endothermic because the positive change in enthalpy means heat is absorbed by the system" (the fourth option among the given choices).
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use the periodic table to answer the question. which element has atoms …
cerium (Ce)
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17) suppose while you were heating your sample, you forgot to cover the…
lower than it should be ### Question 17b
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exothermic reactions question context with options: always release ener…
$\boldsymbol{\text{always release energy}}$ (the option with this text, e.g., the first radio button option)
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valence electrons 1 quick check helium is in group 18 of the periodic t…
B. Helium atoms have 2 valence electrons, while atoms of the other elements in the group all have 8 valence electrons.