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Science

CHECK MY ANSWERS!!!!!!!
1) Cobalt has a mass number of 59 and an atomic number of 27. A student wants to create a model of a cobalt atom. Which statement about the model is correct?(1 point)

A. The model should show 27 protons and 32 neutrons.******
B. The model should show 59 protons and 27 neutrons.
C. The model should show 27 protons and 27 neutrons.
D. The model should show 32 protons and 59 neutrons.

2) In a molecule of lithium sulfide, there are two atoms of lithium and one atom of sulfur. Which statement about lithium sulfide is correct?(1 point)

A) The chemical formula for lithium sulfide is LiS2.
B) The atoms in lithium sulfide are held together by bonds.*****
C) Both lithium and sulfur form positive ions.
D) A molecular model of lithium sulfide would have two spheres.

3)Which element has the same number of valence electrons as bromine (Br)? (1 point)
A) ytterbium (Yb)
B) selenium (Se)
C) krypton (Kr)******
D) astatine (At)

4) Why are sodium (Na) and potassium (K) in the same group on the periodic table?(1 point)
A) They have similar reactivity.*******
B) They are both hard and brittle.
C) They have similar atomic weights.
D) They are both colorless.

5) A student cuts some fabric into two pieces. Is this change physical or chemical?(1 point)
A) It is a chemical change because there is no phase change.
B) It is a chemical change because the size changes.
C) It is a physical change because the process is reversible.
D) It is a physical change because there is no reaction.******

6) How are chemical changes different from physical changes?(1 point)
A) They form new substances.********
B) They are reversible.
C) They involve heat.
D) They include shifts in the phase of matter.

7)A scientist makes several observations about a chemical reaction and records them in the table shown. Which observation contains an error? (1 point) picture added!
A) 1
B) 3
C) 2******
D) 4

8) In a chemical reaction, hydrofluoric acid (HF) and sodium hydroxide (NaOH) combine to form sodium fluoride (NaF) and water (H2O). The reaction uses 20 grams of hydrofluoric acid and 40 grams of sodium hydroxide, and it produces 18 grams of water. How much sodium fluoride does the reaction produce?(1 point)

A) 60 grams
B) 42 grams
C) 18 grams******
D) 78 grams

9)Which procedure could be used to demonstrate that matter is conserved during a physical change?(1 point)

A) Find the mass of an apple. Cut the apple and remove the core. Find the mass of the remaining apple.
B) Find the mass of a raw egg. Cook the egg. Find the mass of the cooked egg.********
C) Find the mass of a cup of water. Boil the water. Find the mass of the water that remains.
D) Find the mass of a piece of ice. Let the ice melt. Find the mass of the liquid water.

10) One molecule of bromine (Br2) and two molecules of potassium chloride (KCl) combine in a reaction. How many atoms are in the products?(1 point)

A) two******
B) four
C) three
D) six

11) Use the unbalanced chemical equation to answer the question.

2NaHCO3 → Na2CO3 + CO2

What can be added to the products to balance the equation? (1 point)

A) CH2OH****
B) H2O
C) H2
D) O2

12) The chemical formula for phosphorus trichloride is PCl3. In one to two sentences, explain how you would build a ball-and-stick model of phosphorus trichloride. Include a description of the parts of the model.(2 points)

13) Copper (Cu) reacts with sulfur (S) to form copper sulfide as shown in the chemical equation. A scientist adds 4 grams of Cu to 2 grams of S to start the reaction. At the end of the experiment, she has 6 grams of product. In one to two sentences, explain what would happen if the scientist increased the amount of copper to 6 grams, and why. (1 point)

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  1. I'm befuddled. This is the same question(s) Damon and I answered yesterday including the same typos, omitted information, etc. What goes?

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    DrBob222
  2. im sorry but i cant find the question

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  3. It's one of the many problems brought on by the changes in this forum. Sorry you lost it. For fear of you losing it again, I will try to repost this question at the top of the page, answer it, and perhaps you will see it before it disappears.

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    DrBob222
  4. I reposted the entire question at the top of the page under "science--repost for Alexa by DrBob222. It may not be the first question by the time you look at it but it will be somewhere near the top of the page.

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    DrBob222
  5. Are these correct

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  6. im sorry but ever since jiskha got updated i really cant find a ton of questions

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  7. are These wrong

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  8. are they correct

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  9. are they correct or not?

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  10. ARE THEY CORRECT I NEED TO KNOW NOW

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  11. @answer me darnit nope she is wrong

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  12. bruvvvvvv is this correct or not i really need to knowwwww

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  13. idk @popi;)

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  14. uh....are they correct or wrong...which one's are correct and which one's are wrong? Please let me know!!!!

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  15. honey bunny which ones are right

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  16. first of all what are the answers

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  17. for connexus kids
    1. b
    2. b
    3. b
    4. c
    5. c
    6. a
    7. b
    8. b
    9. c
    10. c
    11. d
    12 and 13 you answer on yr own < 33

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  18. is they right

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  19. is uhhhh correct

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  20. are they right ?

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  21. has anyone actually taken it yet and found out the correct answers?

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  22. uhhhhh is definitely not correct at all i got two right 😭😭the ones taht she does have right are 7 which is b and 8 which is also b.

    Correct answers are
    1.c
    2.c
    3.a
    4.b
    5.a
    6.c
    7.b
    8.b
    9.b
    10.d
    11.c
    and then the last two are on your own. Yw btw

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  23. There all randomized what are The acttually word answers?

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  24. yo katelyn all those answers are wrong

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  25. there randomized smh so prob not correct.....maybe sum

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  26. @uhhh is completely worng

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  27. alexa, your answers were mostly wrong. i got wrong answers. to anyone who sees this, DONT USE HER ANSWERS.

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  28. Someone please help Im really confused and I bet all of y'all are too

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  29. 1. The model should show 27 protons and 32 neutrons.
    2. The atoms in lithium sulfide are held together by bonds.
    3. astatine (At)
    4. They have similar reactivity
    5. It is a physical change because there is no reaction.
    6. They form new substances
    7. 1
    8. 42 grams
    9. Find the mass of a piece of ice. Let the ice melt. Find the mass of the liquid water.
    10.six
    11. H20
    12 and 13 on your own:)

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  30. what is right can people just say what the answer is or questions and not just spam pleasd

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  31. :) is right!!! tysm

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  32. Yay! Thank you :)!

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  33. I really need help with 12! Can someone pls help me?

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  34. @Connexus girl, i would but im also stuck on that question right now.

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  35. answers]

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  36. The answer that :) forgot to type is 2, it is actually question 8, I guess they shifted

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  37. man I don't understand 13 AT ALL

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  38. omg what is 12 and 13 !>:(

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  39. bruvvvvv

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  40. Aright. I'ma be nice. FOR ONE TIME. ONLY. EVER. Then I'ma go back to repossessing Jack. OKAY?! Here are the best answers I can give yah.

    1. The neutron has a negative charge and is found in the nucleus.

    2. The model should show 27 protons and 32 neutrons

    3. because only two electrons can fit in the first orbit around the nucleus, and each period on the table is organized by number of orbits

    4. The atoms in lithium sulfide are held together by bonds.

    5. Astatine (At)

    6. atomic number

    5. low-energy alpha particles passing through a field of high mass-number-particles

    7. Metals can be hammered into thin sheets, and nonmetals are brittle.

    8. polonium (Po)

    9. silicon (Si)

    10. Hydrogen has one electron and one proton.

    11.Barium has fewer valence electrons, but they are in a higher energy level.

    12. Barium has more valence electrons, and they are in a higher energy level. (Maybe?)

    13. An ionic bond is likely because they will want to give away two valence electrons in order to become stable.

    14. 2-

    15. four

    16. OH

    17. methyl

    18. You could use a red ball for P and 3 yellow for CI. (Change The Colors, wink wink.)

    19. For Instance, Neon (Ne) has an atomic number of 11. It has a completely full Shell of electrons. But Sodium has 1 more proton, AND one more electron. That extra electron is in the outside shell, making a VALENCE electron. (ParaphraseortheywillfindoutandthenyouwillbeDED.)

    20. On the table metals, (which you can find on the left side) the metals will be positive. On the right side, the NON-metals will be negative. (againyoubetterparaphraseyoulittlesonsof)

    Well, that's all, I'm of to mess with jack. (I swear, if he buys one more tub of antiseptic cream for Christmas for me, i'ma SNAP.)

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  41. ^^1,9,11,12 are wrong
    1. the neutron has a negative charge and is found in the nucleus
    9. vanadium(v)
    11. hydrogen doesnt have any neutrons
    12. francium has fewer valence electrons, but they are in a higher energy level
    everything else is good! ty anti, have fun messing w jack<3

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  42. 🧃🧃 number 12 was actually wrong, but thank u for the rest!!!!

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  43. You don't think your teachers know you are cheating when you literally copy the short answers word for word.

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  44. Awesome. Hope it works out for you all. And I will, Double juice man.

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  45. Thank you Äñ↑ΊèÞ†íçé¥ë, and 🧃🧃 was right abt 1, 11, and 12. Idk abt 9 bc I had a different question and y'alls answers weren't options for me but thank y'all so much!

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  46. looks like we are a family now...

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  47. Did someone say... family?

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  48. shot gun

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  49. haha ok but did you know that I'm a box of mints

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  50. OMG, What is the answer for 12 and 13 once I get them I will share all of my answers!!

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  51. The most important thing in life will always be family.

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  52. True Dat

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  53. Guys come on we need to work together to make sure that we have a good grade come on guys let's do this

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  54. I know the first anwer it's the the model should show 27 protons and 32 neutrons

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  55. DO NOT SUBMIT THE TEST IF YOU ANSWERED WITH uhhhh’s ANSWERS I GOT 4/15

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  56. Question 12 Answer

    If you have red balls for phosphorus, the sticks for bonds, and white balls for trichloride, then you would need 1 red ball, 3 sticks, and 3 white balls. the sticks will connect all of the molecules together, with the red ball as the base and then a white ball sticking out of 3 different spots.

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  57. DON'T USE MY ANSWER DIRECTLY. CHANGE IT UP!!!!!!!!!

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  58. Question 13 Answer

    You can weigh the reactants. The mass and products will be the same.

    AGAIN DON'T USE MY ANSWERS WORD FOR WORD!!!!!!!!!!!

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  59. What are the answers to the whole test tho

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  60. Pls help.

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  61. Thanks so much Andrew!

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  62. i promise this is 100% correct
    1. The model should show 27 protons and 32 neutrons.
    2. The atoms in lithium sulfide are held together by bonds.
    3. chlorine (Cl)
    4. They have similar reactivity.
    5. It is a physical change because there is no reaction.
    6. They form new substances.
    7. 1
    8. 42 grams
    9. Find the mass of a piece of ice. Let the ice melt. Find the mass of the liquid water.
    10. six
    11.H2O

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  63. 22 hours ago

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  64. here some awnsers bc yea
    this for ppl who use Conexxus i flunked the test so im just gunna grab awnsers from the awnser key at the end :>

    1.The model should show 27 protons and 32 neutrons.
    2.The atoms in lithium sulfide are held together by bonds
    3.chlorine (Cl)
    4.They have similar reactivity.
    5.Vinegar
    6. 1
    7. It is a physical change because there is no reaction.
    8.They form new substances
    9. 1
    10. 42 grams
    11. Find the mass of a piece of ice. Let the ice melt. Find the mass of the liquid water.
    12. six
    13. H2O
    14 - 15 are writing questions good luck on those endings :> sry if you got these wrong bc they changed the awnsers

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  65. OMGGG I HAVE A DIFFERENT TEST BRO CAN YALL HELP

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  66. AND I HAVE 13 QUESTIONS

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  67. Yeah they changed number 8, tbh idk what to do now :/

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  68. thank god I have a smart sister

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  69. Help!! I HAVE 15 QUESTIONS UHG

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  70. did anyone get anything?

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  71. I have 13 questions helpp

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  72. Correct answer 100%
    The same ones everyone else said but 8 is 58.44 and 9 is find the mass of a peice of ice let the ice melt find the madd of the luquid water

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  73. Good Morning to everyone! I hope for you to read this and understand. DONT listen to the ones with all the answers because everyone's test is different. I'd advise you to search all the answers one by one. It may take a long time but at least you have a chance of getting them right. And for Connexus girl she had the answers for people who use Connexus so if you dont use Connexus then they're probably wrong. Think before you do is what I'll advise to you.

    And good day!

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  74. Thanks @The Connexus Girl buff I think you're right. I'll do that right now. Thanks! <3

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  75. 1. The model should show 27 protons and 32 neutrons
    2. The atoms in lithium sulfide are held together by bonds.
    3. Chlorine
    4. They have similar reactivity
    5. It is physical change because there is no reaction
    6. They form new substances
    7. It shows that no atoms have been gained or lost during the reaction
    8. 58.44 amu
    9: find the mass of a pride of ice. Key the ice melt. Find the mass of the liquid water.
    10. Six
    11. H2O
    12 and 13. Do it yourself.

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  76. K <3 is 100 percent right

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  77. what's the answer for 12 and 13

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  78. Yo can anybody give me their response for 13?

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  79. I suggest people use quillbot.com for paraphrasing and check-plagiarism.com for check plagiarism.

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  80. K <3 is completely correct for CCA

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  81. heres help for 12
    A model aids in visualizing a molecule and understanding its properties.

    In chemistry, models of molecules give us an idea about the arrangement of atoms in the molecules. Usually, the arrangement of atoms in a molecules determines the kind of reactions that the molecule can undergo.

    Models are three dimensional representations of what molecules look like. They help us to conceptualize the possible orientation of atoms and groups in the molecule.

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  82. My question 9 says "How does a balanced chemical equation demonstrate the Law of Conservation of Mass?"

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  83. i need help for 12 and 13. i have the test with only 13 questions

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  84. you guys need to stop cheating right now. if you keep going like this ur not gonna get anything. how are you gonna get a job? by cheating? no! do u think ppl in college will let u cheat? ur actions have consequences, just stop. if u need help there is always ur teachers.

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  85. ik uts it hard and teachers like only give you like and boom they think you know the whoal test well no its hard sometimes to do tests and i dont study soooooo is not ceating its checking your answers and if you tell us stop checking then why you on here agian NOT CHEAT WERE CHECKING

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  86. one number three if it says:
    Which element has the same number of valence electrons as bromine(Br)?
    selenium (Se)
    krypton (Kr)
    potassium (K)
    chlorine (Cl)****

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  87. bro if people are still going to ask answers to 12 and 13 then I rather you really read the question and come up with your own answers.

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  88. For 12 something along the lines of having an object to have makes It easier to understand it

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  89. I just wanted to let yall know that im leaving Jishka for good, one I dont want to change it, and two I dont feel right cheating.. I want to feel proud for my grades. Becides, I dont want to get caught. hopefully someone else reads this, and figures out cheating is not okay.

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  90. i would stop this madness but im in too deep and i messed up by not paying attention in real school now I'm too far behind to just stop cheating

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  91. y'all these teachers change the answer each time so you cant take others answers so i would recommend searching each question and then brainy will pop up and just click on it and READ THE QUESTION THAT WAS ASKED FIRST!!!then get the answer also it is easy to get caught cheating they can see you history for connexus so make sure you use a different email or guest browser :) always here to help

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