Chemie
Chemische Reaktionen, Stöchiometrie, Molekülstrukturen und Elementeigenschaften.
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which substance is used in lotions and cosmetics? o ammonium hydroxide …
acetic acid
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which best describes solubility? o the speed at which a substance disso…
the ability of one substance to dissolve in another
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when dissolved in water, an acid or a base breaks down into o a proton …
a positive and a negative ion.
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a solution has a ph of 2. which best describes the solution? a strong a…
a strong acid
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what ion do acids release in solution? o hydrogen o hydroxide o carbona…
A. hydrogen
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all of the following are treatments for mental health disorders except:…
B. chemotherapy
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which would increase the rate of dissolving salt into water? low temper…
C. more surface area
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which acid is naturally found in foods and can be safe to eat? o sulfur…
citric acid
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which property describes a mixture? it cannot be separated by physical …
It cannot be described by a chemical symbol or formula.
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which type of energy is found in food? a. mechanical b. kinetic c. ther…
D. Chemical
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which symbol in a chemical equation separates the reactants from the pr…
$ ightarrow$
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which balances the equation mg + o₂ → mgo? o mg + 2o₂ → 4mgo o 2mg + 2o…
$2Mg + O_2 ightarrow2MgO$ (the third option in the multiple - choice list)
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lexi is balancing equations. she is finding one equation to be very dif…
D. Atoms in the equation are already in balance.
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what are the products of the combustion of a hydrocarbon? carbon and ox…
B. carbon dioxide and water
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harvey mixes two liquids. which observation of the new mixture most lik…
a cloudy appearance
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which color combination would create a monochromatic color scheme? yell…
B. Different shades and tints of blue
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chemical a and chemical b react in an exothermic reaction. what can be …
More energy will be released from the old substance than the new substance will release to form its chemical bonds.
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which statement about biogeochemical cycles is true? a. plants are a pa…
B. Plants are a part of the nitrogen, carbon, and water cycles.
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question 5 of 10 which of these sentences describes a benefit of fracki…
C. Fracking can reduce the cost of oil obtained from other countries.
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1. explain the difference between a physical change and a chemical chan…
1. Physical change: Molecules unchanged. Chemical change: New molecules formed. 2. Analyze experiment results for patterns. Similar - similar reactions. Conclusion - Claim: Check …
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which type of reaction has the general formula of ab + cd → ad + cb? o …
replacement
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a car burns gasoline as it moves down the road. which energy transforma…
D. Chemical energy to kinetic energy and thermal energy
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which best describes a mixture? it has a single composition, and it has…
It can have different compositions, and it has a set of characteristics that does change.
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thirty grams of lead oxide and fifteen grams of ammonia react completel…
C. 45 g
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which property describes a mixture? it cannot be separated by physical …
It cannot be described by a chemical symbol or formula.
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which solution has the greatest number of hydroxide ions? o baking soda…
Baking soda, pH = 9
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which describes what will happen to the h+ when reactants form products…
$H^+$ binds with $OH^-$ to make water.
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which product contains a strong base that would most likely completely …
A. drain cleaner
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which is formed by positive ions from a base and negative ions from an …
A. salt
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carla is using a fertilizer that contains nitric acid. how is nitric ac…
A. strong acid
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what is the best definition of strategy? (1 point) a way to introduce a…
a plan for achieving something
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apple juice has a lower ph than black coffee. which best explains the r…
Apple juice has more hydrogen ions than black coffee.
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which refers to a measure of how acidic or basic a solution is? ph solu…
pH
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which would be least likely to completely dissolve in water? o hydrochl…
D. acetic acid
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which is the order of these solutions from strong acid to strong base? …
B. battery acid → stomach acid → antacid → baking soda → household ammonia
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which option is an isotope with 6 protons and 8 neutrons? (1 point) car…
carbon - 14
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analyze 1. which of the changes you observed indicated a physical chang…
1. No specific changes given, can't answer. 2. Varies by experiment, e.g., measurement errors; improve with better controls. 3. Physical: external property change. Chemical: new -…
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a nitrogen ion has a mass of 14 and a charge of +2. which subatomic par…
7 protons, 7 neutrons, and 5 electrons
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which atom would be neutral? (1 point) an oxygen atom with 8 electrons,…
An oxygen atom with 8 electrons, 8 protons, and 9 neutrons
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atomic composition quick check how is the mass number of an atom calcul…
protons plus neutrons
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erika made a mistake in her table. which best describes the mistake eri…
None of the above options are correct as written. But if choosing the most incorrect, A and B misstate key metal/non - metal properties severely.
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most metals\tmost nonmetals good conductor\tpoor conductor high melting…
The table has incorrect information about malleability and melting points of metals and non - metals.
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strontium and calcium form 2+ ions. strontium has one more shell than c…
1. Strontium and calcium form 2+ ions. - True 2. Strontium has one more shell than calcium. - True 3. Strontium has more electrons than calcium. - True 4. Strontium and calcium te…
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why is it essential to life that water has a high heat capacity? water’…
Water’s high heat capacity allows it to absorb a large amount of heat before increasing in temperature, allowing humans to maintain a steady body temperature.
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which two statements can best explain why strontium binds to bone tissu…
Strontium and calcium form 2+ ions.
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based on the information in the periodic table, how does titanium (ti) …
D. Titanium is a solid, and fluorine is a gas
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based on the information in the periodic table, how does titanium (ti) …
D. Titanium is a solid, and fluorine is a gas.
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which element behaves the most like calcium and why? k, because it is i…
Be, because it is in the same group and has same number of valence electrons.
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which element behaves the most like calcium and why? ○ k because it is …
Ba, because it is in the same group and has same number of valence electrons.
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preview each experiment you will perform. for each experiment, is the c…
To determine if a change is physical or chemical, observe for new - substance formation and signs such as color change, gas evolution, or heat changes.
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atom ion isotope - a potassium atom has equal numbers of protons and el…
The statement "a potassium ion has one less electron than protons giving it a negative charge" is incorrect. A potassium ion has a positive charge.
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why does a layer of ice form on the surface of a pond during freezing w…
Molecules of water in the solid phase are less dense than those in the liquid phase.
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atom ion isotope - a nitrogen atom has an equal number of protons, neut…
The descriptions about atom, ion, and isotope of nitrogen are correct.
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famous friday - for the following famous scientist, you must research w…
Percy Julian was a prominent chemist known for his work in synthetic steroid - based drugs. He overcame racial obstacles in science and made significant contributions to the synth…
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hands - on lab exploring physical and chemical changes all substances a…
Examples of physical changes: melting ice. Chemical changes: burning wood.
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which change would decrease the ph of a base in a solution at equilibri…
D. decreasing the concentration of $OH^-$ ions
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use the information in the table to answer the question. acid solutions…
HA, HC, HB
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hydrochloric acid is a strong acid. acetic acid is a weak acid. which s…
The dissociation constant for hydrochloric acid is greater than the dissociation constant for acetic acid.
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which acid - base chemical reaction is irreversible? (1 point) weak bas…
strong acid added to water
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pre - ap chemistry bellwork 9/5 students collect mass and volume data f…
$14.5\ g/ml$
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which three models display the structure of an atom, its ion, and its i…
The three models labeled Atom, Ion, Isotope
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question 1 - 8 why does a layer of ice form on the surface of a pond du…
Molecules of water in the solid phase are less dense than those in the liquid phase.
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which term describes when two atoms of the same element have different …
C. Isotopes
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what is the atomic number of an oxygen atom with 8 protons and 10 neutr…
8
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what does the electron cloud model describe? the group of protons that …
location where an electron has the highest probability of being found
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how many protons are in this atom if it has a balanced charge? 0 2 4 6
B. 2
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which statement best describes the electrons in this illustration? the …
The electrons are negatively charged particles located outside the nucleus
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freezing is a phase change from a ______ to a ______. a. solid; liquid …
D. liquid; solid
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select the correct answer. samuel adds a teaspoon of salt to a glass of…
B. It's a physical change because the water and the salt kept their original properties.
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select the correct answer. carbon burns in the presence of oxygen to gi…
B. carbon + oxygen → carbon dioxide
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select the correct answer. what kind of chemical reaction does the chem…
D. synthesis
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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 | | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | Boron | B | 11 | 5 | 5 | 6…
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in the author to her book, the main reason bradstreet uses inversion is…
complete the rhyme scheme.
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what is atomic mass? o the mass of the atom based on the mass of an ato…
the mass of an atom based on the mass of an atom of carbon-12
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which term describes atoms with different atomic masses due to varying …
C. isotopes
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carbon has an atomic number of 6 and a mass of 12. carbon - 14 is a nat…
C. 8
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directions: using the physical properties of substances listed in the t…
First, use a magnet to separate the nickel from the mixture of water, oil, dirt and nickel. Then, let the remaining mixture settle and decant the oil layer. Finally, filter the re…
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a neutral atom of which element contains 10 electrons? a. boron b. fluo…
D. neon
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what happens to the gas when a gas is compressed and the molecules are …
It rises in temperature
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model 1 - copper samples group number volume (cm³) mass (g) substance 1…
Copper
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question 20 5 pts a poem with 14 lines that is written in a well - defi…
D. sonnet
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how does a chlorine atom become a negatively charged ion? a. it gains a…
A. It gains an electron.
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which of the following is most chemically like sulfur (s)? a. oxygen (o…
A. Oxygen (O)
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pure substances are made up of only one type of atom or compound, where…
C. milk
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on the periodic table, the elements in the columns have the same a. den…
D. number of valence electrons
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question select all the correct answers. which actions show that mixing…
purifying water with a carbon filter, a soda fizzing when its cap is opened, a metal mixed with a very small amount of a nonmetal to make a metallic alloy
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question select all the correct answers. which observations show that a…
B. Overnight, dew forms on the grass.
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gain two electrons are found in group two atoms will be positive ions i…
A. Alkaline earth metals do not gain two electrons, they lose two electrons.
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what defines a mixture? a. can be broken down into its basic parts thro…
A. can be broken down into its basic parts through physical means
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question select the correct answer. a scientist compares two samples of…
Density calculations show that the gases are different, so a chemical reaction occurred.
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which ion has a charge of 2+? a. an ion with 10 protons, 10 neutrons, a…
B. an ion with 10 protons, 9 neutrons, and 8 electrons
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question select all the correct answers. which of these events indicate…
Silver jewelry becomes dark because of tarnish., A solid appears when two water-based solutions are added together.
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which of the following interactions results in a new substance? i. when…
A. II and III only
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pure copper metal has a very high conductivity. brass, an alloy of copp…
A. because the physical properties of the mixture are different than its components
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which of the following is formed when two or more different kinds of at…
B. compound
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lisa had an unknown clear liquid in a beaker. after heating on a hot pl…
A. a mixture
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sewage treatment plants use settling tanks to separate raw sewage into …
C. heterogeneous
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how can damage to living things occur from exposure to x - rays or gamm…
A. Atoms and molecules in the body can be ionized.
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the periodic table organizes the 118 known chemical elements. which pro…
A. atomic number, which is equal to the number of protons in an atom
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question type your response in the box. a reddish layer of rust can for…
Reactants: Iron and Oxygen; Product: Iron Oxide. Word equation: Iron + Oxygen react to form Iron Oxide.