化学
化学反应、化学计量、分子结构与元素性质。
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in your lab group you combined vinegar and baking soda and observed the…
A. A gas is produced C. Bubbling occurred E. There is a change in the composition of the reactants
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look at each answer choice. decide whether it is an example of a chemic…
Chemical Change: Pouring baking soda into vinegar, Lighting a match, An iron nail slowly rusts and turns reddish - brown Physical Change: Breaking a matchstick, Putting two cubes …
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1. state whether each of the following laboratory safety precautions is…
1. (a) True (b) True (c) True (d) True (e) True (f) True (g) True (h) True (i) True (j) True (k) True (l) True (m) True (n) True 2. (a) acids (b) bases (c) alcohol
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which of the following is a chemical change? check all that apply. ripe…
burning a log, ripening a banana
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a physical change can be described as a change that doesnt affect the c…
Physical change: ice melting, matter is conserved, change in shape or phase Chemical change: rusting of a nail, a raw egg is fried, nitrogen gas and hydrogen gas combine and form …
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which is an example of a chemical change? a glass melts in a furnace b …
C. newspaper decays in a landfill
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3. state whether each of the following laboratory instructions is true …
(a) False (b) True (c) True (d) True (e) True (f) True (g) True (h) True (i) True (j) True If any chemical comes in contact with your skin, immediately flush the affected area wit…
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when the change in part 3 occurs, does the sample have different chemic…
If it's a chemical change, yes, different chemical properties. If it's a physical change, yes, different physical properties. So both "Yes, different physical properties" and "Yes…
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part 2 of 4 under a second set of conditions, the same substances mix a…
We need more information about what happens in parts 2 and 3 (specifically what the changes in C and D are) to determine if it is a physical change, chemical change, or both. With…
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enter the symbol of a sodium ion, na⁺, followed by the formula of a sul…
$Na^+,SO_4^{2 - }$
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part 1 of 4. scenes a - d represent atomic - scale views of different s…
Chemical change
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part a enter the molecular formula for butane. c₄h₁₀
$C_4H_{10}$
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18. create your own real - world example where properties of matter, ac…
A real - world example is a battery - powered flashlight. Properties of matter (like conductivity of metal electrodes) are important for electricity flow. Acids/bases (electrolyte…
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name _ score / 100 warm up stoichiometry show your solution/work (no wo…
Limiting reagent: $Cl_2$ Excess reagent: $Na$
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part d - mixed review 16. explain how the law of conservation of mass c…
The Law of Conservation of Mass is related to properties of matter as it is based on the fact that atoms, which define matter's properties, are conserved in acid - base reactions.…
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4. the ph of a newly filled pool is tested and found to be slightly aci…
Add sodium bicarbonate to raise pH. This helps maintain good water quality, protects swimmers and equipment.
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10. compare mixtures and pure substances. give two examples of each.
Pure substances: gold (a pure element), water (a pure compound). Mixtures: salt - water solution (a homogeneous mixture), trail mix (a heterogeneous mixture).
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4. sep construct an explanation a fireworks designer is planning a red-…
For red: strontium salts (emits red - orange light from electron transitions). For white: magnesium or aluminum powders (burn brightly to give white light). For blue: copper compo…
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4. rank three samples in order of increasing (a) number of particles, (…
(a) Sample 4, Sample 3, Sample 2, Sample 1 (b) Sample 4, Sample 1, Sample 2, Sample 3 (c) Sample 4, Sample 3, Sample 2, Sample 1
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which three elements are found in every carbohydrate? hydrogen phosphor…
Hydrogen, Oxygen, Carbon
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part b - properties of matter 8. identify whether each is a physical or…
a) Physical b) Chemical c) Physical d) Chemical
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4. rank three samples in order of increasing (a) number of particles, (…
(a) Sample 2, Sample 1 (b) Sample 1, Sample 2 (c) Sample 2, Sample 1
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2 solve apply the concepts to this problem. all nonzero digits are sign…
The area should be reported to four significant figures.
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2. sep obtain information what problem occurs if the firework mixture i…
Inconsistent burning, affected explosion color and intensity, mis - fires or premature explosions.
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7. draw a bohr model for sodium (na). atomic number = 11, atomic mass =…
To draw the Bohr - model: 1. Draw a small circle in the center to represent the nucleus. Write "11p" (for 11 protons) and "12n" (for 12 neutrons) inside the nucleus. 2. Draw three…
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investigative phenomenon authentic reading firework colors chemistry sy…
When fireworks are ignited, elements and compounds absorb energy, causing electrons to move to higher energy - levels. As electrons return to lower energy - levels, they emit ligh…
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part d. isotopes. 1. complete the table below with the correct isotope …
1. See table above. 2. Draw a nucleus with 8 protons and 9 neutrons, and two electron - shells with 2 and 6 electrons respectively. 3. Difference: number of neutrons (lithium - 7 …
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3. oxygen has an atomic number of 8 and an atomic mass of 16. how many …
Protons: 8, Neutrons: 8, Electrons: 8
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which three elements are found in every lipid? some lipids contain addi…
carbon, oxygen, hydrogen
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solve each of the following problems. show all your work and remember t…
1. Approximately $7.37\%$ 2. Approximately $0.51\%$ 3. Approximately $0.75\%$ 4. Approximately $1.69\%$ 5. Approximately $0.023\%$
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total recall 1. what are the common physical states of matter? 2. how d…
1. Solid, liquid, gas 2. Solid particles are closely - packed and vibrate in place; liquid particles are close and can move past each other; gas particles are far apart and move f…
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according to this chronological organization system, where should this …
In the front of the Chemistry section
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which atom is which! every kind of atom has its own unique look. all th…
Without the actual count of protons in each atomic model (as the image details are not fully described in text), we cannot provide specific element names. If you can provide the n…
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there is a table (not one for dinner) thats probably the most famous ta…
1. a. 1; b. 1 2. a. Magnesium; b. 12 3. a. 26; b. Fe 4. a. 5; b. Boron 5. a. 79; b. 79; c. 79; d. Gold 6. a. 59; b. Ni 7. a. Na; b. 12; c. Sodium 8. a. 78; b. 117 9. a. Lead; b. 8…
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discussion topic the subject of earth and space science is a vast topic…
A scientist in Earth and Space Science might conduct fieldwork in natural settings for data collection which is different from a chemist's lab - based work. Similarities exist in …
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3. joe and his dad build a campfire out of 5 kilograms of wood. after t…
4 kilograms
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10 multiple - choice 1 point the elements of a heterogeneous mixture ca…
That you can see the different component parts of the mixture.
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which of the following is an example of a chemical element? salt water …
Sodium
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which of the following is a heterogeneous mixture?
None of the above
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which of the following two ingredients can combine to make a compound? …
B. Hydrogen and Oxygen
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subatomic particles worksheet (fill in the missing information) element…
The completed table is shown above.
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what is true of a compound? it does not always retain the properties of…
It does not always retain the properties of the substances that make it up.
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based on the information from the movie, what can you conclude about th…
D. It's water.
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what is true of a mixture? it is always thicker than the two chemicals …
It retains the properties of the substances that make it up.
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what occurs during a chemical reaction? atoms of two or more elements a…
Atoms of two or more elements bond together.
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1 multiple choice 1 point how is a compound different from a mixture? m…
Mixtures are created through physical means; compounds are created through chemical reactions.
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10 true or false 1 point a mixture can contain both individual elements…
True
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multiple choice 1 point if you can easily see the different parts of a …
A. heterogeneous
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if you are looking under a microscope at blood (as pictured here), do y…
heterogeneous
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what kind of mixture do you think gasoline is? heterogeneous homogeneou…
B. homogeneous
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what would an example of a heterogeneous mixture? nail polish remover k…
D. Pizza
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what would be an example of a homogeneous mixture? chex mix salt water …
B. salt water
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physical properties such as density, boiling point, and melting point a…
B. False
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if i have two or more different types of substances blended together bu…
True
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mathxl for school: practice & problem solving (lms graded) part 2 of 2 …
$1.3\times 10^{-18}$ grams
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pure substances are made up of one type of element or compound made up …
Made up of one type of element or compound
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a scientist is determining the mass of 24,000 molecules of oxygen. use …
2
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protons, neutrons, and electrons practice worksheet calculating the num…
| Name of Element | Element Symbol | Mass Number | Atomic Number | Protons | Neutrons | Electrons | |---|---|---|---|---|---|---| | Yttrium | Y | 89 | 39 | 39 | 50 | 39 | | Copper…
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is this sentence in active voice or passive voice? in 1949, the u.s. fo…
active voice
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vijay likes to make rock candy to share with his friends. he normally m…
"He then predicted that smaller sugar granules would lead to larger sugar crystals."
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from elements to subatomic particles directions: determine the requeste…
6. Protons: 6, Neutrons: 6, Electrons: 6, Atomic Mass: 12, Atomic Number: 6, Element Symbol: C, Element Name: Carbon, Ion: no, Charge: 0 7. Protons: 7, Neutrons: 7, Electrons: 7, …
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the second picture is an example of a(n) ______ mixture. heterogeneous …
No picture is provided to determine if it's heterogeneous or homogeneous. So, cannot be answered with given information.
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the first picture is an example of a(n) ________ mixture. ○ heterogeneo…
We need to see the picture to determine if it is A. heterogeneous or B. homogeneous.
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the picture of oil and water on the screen is an example of a _________…
heterogeneous
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how do we define a mixture? something that can only be broken down by a…
B. A substance that can be separated by physical processes
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4 multiple choice 1 point water is classified as ___ an element a mixtu…
C. a compound
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if a substance has freely moving molecules and does not have a fixed vo…
C. gas
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photo by jay galvin in the photo above, a large glacier is creating a v…
C. erosion by ice
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if a substance has a fixed volume and fixed shape, and the molecules ar…
solid
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if a substance has a fixed volume (meaning takes up a specific amount o…
B. liquid
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what is the state of matter below the melting point? liquid solid gas p…
B. solid
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multiple choice 1 point what is the temperature at which a liquid becom…
A. boiling point
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the temperature at which a solid becomes a liquid is called? boiling po…
C. melting point
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sublimation and deposition skip over what state of matter? solid liquid…
B. liquid
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photo by mahlum in the photo above, lichen and fungi are slowly causing…
A. chemical weathering
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2 multiple choice 1 point what is the energy of movement called? heat e…
C. Kinetic energy
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1 multiple choice 1 point is a change of state classified as a physical…
physical
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which observations from the investigations provide evidence that a chem…
No answer can be given without details of investigations.
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which of these would be considered evidence that a chemical change has …
A. A gas is produced C. A temperature change occurs
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amanda wants to make a cake. she measures sugar, eggs, oil, flour, and …
C. Baking the mixed ingredients because the ingredients change into a different substance.
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which of the following best explains what happens when a popsicle melts…
B. It is a physical change because it can be easily reversed.
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identifying atoms worksheet: from elements to subatomic particles direc…
6. Protons: 6, Neutrons: 6, Electrons: 6, Atomic Mass: 12, Atomic Number: 6, Element Symbol: C, Element Name: Carbon, Ion: no, Charge: 0 7. Protons: 7, Neutrons: 7, Electrons: 7, …
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question 1 ___ is formed when ultraviolet radiation decomposes chlorina…
1. B. Phosgene 2. (Option C seems cut - off, assuming it's Nomex, if so) C. Nomex
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the chemical formulas of three substances are shown below. - c₂h₆o - c₄…
elements; elements; chemical formulas
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based on the electron dot diagram, what ion charge would it create? * +…
-2 (corresponding to the option with the value - 2)
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which of the following can not be an ion? * aluminum hydrogen carbon br…
Krypton
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when beryllium becomes an ion it will ___(a)___ electrons as it ___(b)_…
a. lose b. empties c. cation
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electrons that are in the last/outer energy level of an atom are called…
Valence electrons
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match the scientist with their discovery. * dalton thompson rutherford …
Tiny indestructible spheres: Dalton Atoms have energy levels that contain different number of electrons: Bohr Protons, Neutrons & Electrons all exist: Chadwick Tiny dense nucleus …
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which of the following is a neutral atom with 9 electrons? * fluorine s…
A. Fluorine
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what element is shown in the photo below? * 11 p 12 n vanadium aluminum…
Sodium
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which of the following would result in a neutral atom? * 2 electrons + …
12 electrons + 12 protons
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an atom has 26 protons, 30 neutrons, and 26 electrons. what is its mass…
For the first question: B. 56 For the matching part: Positive charge: Protons Negative charge: Electrons Has no charge: Neutrons For the chart - filling part: Neutrons: Has mass E…
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ii. match the vocabulary word to the correct definition 1. cohesion a. …
1. e 2. g 3. a 4. f 5. d 6. b 7. c
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1. write the property of water that matches the picture. water force of…
Polarity, Surface Tension, Polarity, Capillary Action
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4. zinc phosphide, zn₃p₂, is often used as a rat poison. phosphorus has…
4. 2 5. C. $Rb_3N$
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3. a user is constructing an ionic bond between beryllium and chlorine …
Transfer an electron from the beryllium atom to the chlorine atom.
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2. which of the following is the best description of how electrons are …
A. A metal atom loses electrons and a nonmetal atom gains electrons.
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introduction: the periodic table arranges elements by size and property…
1. B. Sodium (Na) C. 1 2. Beryllium: 2, Magnesium: 2, Nitrogen: 5, Phosphorus: 5, Oxygen: 6, Sulfur: 6, Fluorine: 7, Chlorine: 7
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for each compound, click the camera ( ) icon to take a snapshot. right …
Ionic charges: Be $2+$, N $3 -$ Chemical formula: $Be_3N_2$