Answer:
yes eating the food involves both physical and chemical changes. The chewing of food is a physical change, while the mixing of saliva with food triggers chemical reactions
Explanation:
Once the food mixes with the saliva in our mouth, chemical reactions start taking place in the food, leading to its breakdown and changes in its chemical composition. An evidence of the chemical changes is the taste that we feel when we eat something sweet or sour etc.
Answer:
a chechimal
Explanation:
hhelp will give brainliest
Answer: pretty sure it is D
Answer:
its the last one
Explanation:
Do You Know That If you put a Grape in the microwave it will go on Fire!?
Answer:
really?!?! well did u know oranges can get stale??
Which of the following statements is true about single-replacement reactions?
1)They are restricted to metals.
2)They involve a three products.
3)Both the reactants and products consist of an element and a compound.
4)Any metal replaces any other metal.
Explanation:
i think is, They involve a three products.
The statement which is true about single-replacement reactions are:
3) Both the reactants and products consist of an element and a compound.
Single-replacement reactions :These reactions are also known as single displacement reactions, in this type, the ions of the metals or elements get exchanged with the other element and lead to the formation of a new product.
Example: [tex]2K+2H_2O--- > 2KOH+H_2[/tex]
The ions of water get exchanged with potassium and form a new salt that is potassium hydroxide.
Thus, option 3 is correct.
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Calculate the percentage composition of a hypothetical compound, X2Y3. The molar mass of X is 4.53 g/mol and the molar mass of Y is 8.71 g/mol. Round both answers to whole numbers.
Answer:
Explanation: Don't let anyone bring you down you got this you matter, and rock!
HELP ASAP
1. Where are hurricanes most likely to form?
a Over warm tropical waters
b Over frozen Arctic Waters
c Over a tropical rainforest
d Over cool Atlantic Waters
Answer:
Hurricanes are the most violent storms on Earth. They form near the equator over warm ocean waters. Actually, the term hurricane is used only for the large storms that form over the Atlantic Ocean or eastern Pacific Ocean. The generic, scientific term for these storms, wherever they occur, is tropical cyclone.
im going to guess the answer is A, sorry if im wrong.
hope this helps.
Catalysts, including enzymes, have the role of Select one: a. changing a nonspontaneous chemical reaction to spontaneous. b. lowering the activation energy of a reaction. c. heating up the reactants to make the reaction progress faster. d. changing the pH to a favorable pH for the reaction to progress.
Answer:
Lowering activation energy of a reaction.
Explanation:
Activation energy is the minimum amount of energy required by the reactants just to be converted to products.
Since catalysts increase the rate of reaction, activation complex is reached in short period of time hence activation energy is lowered.
During photosynthesis what takes place under the leaf
Answer:
In plants, the process of photosynthesis takes place in the mesophyll of the leaves, inside the chloroplasts. Chloroplasts contain disc-shaped structures called thylakoids, which contain the pigment chlorophyll.
Explanation: Hope this helps
10.0 grams of a gas occupies 12.5 liters at a pressure of 42.0 mm Hg. What is the volume when the pressure has increased to 75.0 mm Hg? 6.72 L 7.00 L 22.3 L 0.143 L
Answer: 7.00 L
Explanation:
Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
[tex]P\propto \frac{1}{V}[/tex] (At constant temperature and number of moles)
[tex]P_1V_1=P_2V_2[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 42.0 mm Hg
[tex]P_2[/tex] = final pressure of gas = 75.0 mm Hg
[tex]V_1[/tex] = initial volume of gas = 12.5 L
[tex]V_2[/tex] = final volume of gas = ?
[tex]42.0\times 12.5=75.0\times V_2[/tex]
[tex]V_2=7.00L[/tex]
Therefore, the volume when the pressure has increased to 75.0 mm Hg is 7.00 L
At what rate does magma deep below Earth's surface cool? What size of crystal results from magma cooling deep below Earth's surface?
O A. Slowly, large crystals form
B Quickly, large crystals form
C. Slowly, small crystals form
D. Quickly, small crystals form
Answer:
i think it is A
Explanation:
i got this answer from a good friend
The magma deep below Earth's surface cool slowly.Large crystals form results from magma cooling deep below Earth's surface. Therefore, option A is correct.
What is magma ?Magma is the molten or semi-molten natural material that gives rise to all igneous rocks. Magma can be found beneath the Earth's surface, and evidence of magmatism has been discovered on other terrestrial planets and natural satellites.
When magma slowly cools deep within the crust, the resulting rock is known as intrusive or plutonic. Because of the slow cooling, crystals can grow large, giving intrusive igneous rock a coarse-grained or phaneritic texture. Individual crystals in phaneritic texture can be seen with the eye.
Intrusive igneous rocks form when magma slowly cools and solidifies beneath the Earth's surface. Large, well-formed crystals are found in intrusive igneous rocks such as granite, gabbro, diorite, and dunite.
Thus, option A is correct.
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What is the mass of 2.25 mol of the element Iron (Fe)?
Choose the correct set up from the given choices.
a. You would divided 2.25 mol by (55.84 mol divided by 1 gram)
b. You would multiply 2.25 mol by (1mol divided by 55.84 g)
c. You would multiply 2.25 mol by (55.84g divided by 1 mol)
d. You would divide 2.25 mol by (1 mol divided by 55.84g)
Mole measure the number of elementary entities of a given substance that are present in a given sample. To find mass of 2.25 mol of the element Iron (Fe), we multiply 2.25 mol by (55.84g divided by 1 mol). Therefore option c is correct option.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance.
Mathematically,
Mole of Fe element= mass of Fe element÷ Molar mass of Fe element
mass= Mole of Fe element ×Molar mass of Fe element
Substituting the given values in above formula we get
mass= 2.25 mol× 55.84 g/mole
mass= 2.25 mol× 55.84 g/mole
To find mass of 2.25 mol of the element Iron (Fe), we multiply 2.25 mol by (55.84g divided by 1 mol).
Therefore option c is correct option.
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CH(4)+ 20(2)→ CO2+ 2H(2)O
22.
The reaction shown above is an example of a -
a. synthesis reaction
b. combustion reaction
c. decomposition reaction
d. double displacement reaction
Answer:
Reaction is a Combustion reaction
For complete combustion of an organic compound needs 8 molecules of oxygen, what could the formula of this compound be?
Answer:
C5H12.
Explanation:
The compound will be C5H12.
Now consider the general formula for the combustion of an alkane;
CnH2n+2 + 3n+1/2O2-----> nCO2 + (n+1) H2O
If we substitute n=5, we have;
C5H12 + 8O2-----> 5CO2 + 6H2O
Hence the answer above.
Which of the following measurements are recorded to three significant figures? Select all that apply.
Select one or more:
a. 0.003 L
b. 140 g
c. 1,610 s
d. 0.0890 m
Answer:
c) 1610 s
d) 0.0890 m
Explanation:
Significant figures:
The given measurement have four significant figures 1234.
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.03 in this number only one significant figure present which is 3.
Zero between the non zero digits are consider significant like 104 consist of three significant figures.
The zeros at the right side when decimal point is present e.g 2400. are also significant. There are four significant figures are present.
a) 0.003 L
This measurement have 1 significant figure which is 3.
b) 140 g
This measurement have 3 significant figure 1, 4. In this measurement 0 is trailing zero that's why it is not consider significant.
c) 1610 s
This measurement have 3 significant figures 1, 6, 1.
d) 0.0890 m
This measurement have 3 significant figures 8,9 and 0
Use the drop-down menus after each statement to identify the dry climate region being described.
v climates feature hot summers and cold winters, dividing the climate into sharply contrasting
seasons.
v climates are characterized by very little rainfall, hot summers, and mild winters.
v climates have annual precipitation between 15 and 25 inches.
Semiarid climate regions have areas of grasslands, called
steppes.
Answer:
✔ semiarid
✔ desert
✔ semiarid
✔ steppes
.
Explanation:
The deserts and steppes comprise the regions that are characterized by dry climates. The dry climates are characterized by very little rainfall, hot summers, and mild winters. The correct option is B.
What is a dry climate?The areas which are very dry and where the water escapes and leaves the area drier than other places is known as the dry climate. Most dry climates have summers very hot, winters cool and warm and the air is very dry.
The main characteristic feature of the dry climate is the low and infrequent rainfall. Arid and semi desert areas have only about 35 cm rainfall per year.
Thus the correct option is B.
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A chipmunk (mass of approximately 1 kg) does push-ups by using a force of 5 N to elevate its center-of-mass by 6 cm in order to do 0.70 Joule of work. If the chipmunk does all this work in 2 seconds, what is its power?
Answer:
Approximately [tex]0.35\; \rm W[/tex] on average.
Explanation:
There are multiple to find power:
Power [tex]P[/tex] is equal to the product of force [tex]F[/tex] and the speed [tex]v[/tex] at which that force moves the object. That is: [tex]P = F \cdot v[/tex].On the other hand, average power [tex]P[/tex] is also equal to the rate at which work [tex]W[/tex] is done. In other words, average power [tex]P\![/tex] is the average work done in unit time. If work [tex]W\![/tex] is done in time [tex]t[/tex], the average power would be [tex]P = W / t[/tex].The question did not state the speed at which the arm of the chipmunk moves. However, the question did state the work done ([tex]W = 0.70\; \rm J[/tex]) and the time required ([tex]t = 2\; \rm s[/tex]).
Therefore, the equation [tex]P = W / t[/tex] seem to be more suitable.
[tex]\begin{aligned}&P\\ &= \frac{W}{t} \\ &= \frac{0.70\; \rm J}{2\; \rm s} \approx 0.35\; \rm W\end{aligned}[/tex].
2b. 12 grams of C8H18 react with oxygen to produce carbon dioxide and water. How many grams of CO2 are produced?
12.4
13.5
11.6
37.1
Other:
Answer:
37.1g are produced
Explanation:
The combustion of C₈H₁₈ is:
C₈H₁₈ + 25/2O₂ → 8CO₂ + 9H₂O
Where 1 mole of C₈H₁₈ produce 8 moles of CO₂
To find the mass of CO₂ that is produced we need to convert the mass of C₈H₁₈ with molar mass. Then, with the chemical equation, we can find the moles of CO₂ and its mass, as follows:
Moles C₈H₁₈ -Molar mass: 114.2g/mol-
12g C₈H₁₈ * (1mol / 114.2g) = 0.105 moles of C₈H₁₈
Moles CO₂:
As 1 mole of C₈H₁₈ produce 8 moles of CO₂, 0.105 moles of C₈H₁₈ produce:
0.105 moles of C₈H₁₈ * (8moles CO₂ / 1mole C₈H₁₈) = 0.84 moles of CO₂
Mass CO₂ -Molar mass: 44.01g/mol-:
0.84 moles of CO₂ * (44.01g / mol) = 37.0g of CO₂ ≈
37.1g are producedWhich is most likely to be damaged by an acid? A. A glass jar B. A plastic bottle C. A gold bracelet D. An aluminum can
Answer:
aluminum can
Explanation:
source: trust me bro im currently working on acid and bases and acid doesnt eat through gold
The object which is most likely to be damaged by an acid is Choice D: An aluminium can.
When an acid undergoes ionization in an aqueous solution, the positively charged ion released is; Hydroxonium ion, H30+.
In essence, the hydrogen ion of an acid can be displaced by the Aluminium ion in the aluminium can.This phenomenon is evident in the arrangement of metals in the electrochemical series.Aluminium is more reactive than the hydrogen ion. As such, an Aluminium can is most likely to be damaged by an acid.
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I can be found in the 4th period on the periodic table.
Vanadium (V)
Zirconium (Zr)
Carbon (C)
Beryllium (Be)
Vanadium (V)
Vanadium is the only one in the 4th period here so
___SeCl6+ ____ O2——> ___ seO2 +___Cl2
If you can do this I need help with more
Answer:
SeCl6 + O2——> seO2 + 3Cl2
An element in group 3 that is a good conductor of electricity.
Answer:
Well for me I think
Explanation:
it's Aliminium
Answer:
Aluminum is good in heat and conductor
Where are chlorofluorocarbons (CFCs) found? Why were they banned?
Answer:
A gaping hole in the ozone layer over Antarctica was discovered in the mid 1980s. The international community agreed the Montreal Protocol in 1987, which banned most of the offending chemicals.
Hope this helps..A pure substance is one that_____
a. Has been filtered
b. is an element or compound
c. If found in nature
d. Has been cleaned
Answer:
gimme points
Explanation:
What kind of bond would form between an iron and an oxygen atom: ionic, covalent, or metallic? What kind of bond would form between two silver atoms: ionic, covalent, or metallic? What happens to the valence electrons in this bond? How do ionization energy and electronegativity help explain why this occurs? 3) What kind of bond would form between two chlorine atoms: ionic, covalent, or metallic? What happens to the valence electrons in this bond? How do ionization energy and electronegativity help explain why this occurs?
Answer:
See explanation
Explanation:
Since iron is a metal and oxygen is a non metal, a bond is formed between the two when electrons are transferred from iron to oxygen. Hence the bond is ionic.
Two silver atoms are held together by metallic bonds. Metallic bond are bond forces that exist between metal atoms in a crystal lattice. The valence electrons in this bond form a cloud. Metals have low ionization energy and low electronegativity hence they loose electrons easily. This accounts for the nature of the metallic bond.
The bond formed between two chlorine atoms is a covalent bond. The valence electrons in this bond are localized between the two chlorine atoms. Chlorine is a nonmetal hence it has a high ionization energy and high electronegativity. Hence it forms covalent bonds in which electrons are shared between bonding atoms.
What coefficient is needed to balance this equation? ____Fe + 4H2O --> Fe6O4 + 4 H2 *
Answer:
the answer is 1
the coefficient needed to balance this equation is 1
Explanation:
can someone help me??
Which action is a result of gravity in relation to moving tectonic plates?
Earth's internal heating
circulating material in the mantle
ridge push and slab pull
Earth's magnetic field reverses
Answer:
I do K12 and c is correct!
Answer: B. ridge push and slab pull
Explanation: Took the test.
Why does soap work to remove oil? (Note that most oils can be considered non-polar. A soap molecule has one end that is polar and one end that is non-polar.)
Answer:
Soap breaks up the oil into smaller drops, which can mix with the water.
Explanation:
This works because soap is made up of molecules with two different ends.
The soap molecules works as a surfactant for the water oil interphase. The hydrophobic head of the soap molecules trap the oil and dirt ad remove from the surface.
What are surfactants?Surfactants are chemical substances used to reduce the interfacial tension between substance boundary. Soaps and detergents acts as surfactants which are used to remove the dirt and oil from material surface.
Soap has both polar and non-polar characteristics. The alkaline part in the soap causes it to have a polar head, and because of the electric charge on this head, the soap is hydrophilic. A hydrophilic part of soap is drawn to water and will cling to it.
In this instance, the positive-charged hydrogen atoms of the water's hydrogen atoms match with the polar head of the soap molecule. The other part of soap is a fatty acid tail, which is hydrophobic and can bind with the oil and dirt. The trapped oil molecules are then be removed by water.
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13. Sodium, Na, shows metallic properties. Identify another element that is likely to show similar metallic properties.
Answer:
19.K, potassium
Explanation:
it has all properties of metals
Find the mass of 7.00 mol of H2O2?
Answer:
238g
Explanation:
Molar Mass (1 mol) of H2O2 = 34.0147 g/mol
7.00 mol = 35.0147*7
= 238.1029g
= 238g (rounded to 3 sig figs because 3 sig figs in 7,00)
Answer:
answer in picture
Explanation:
Use your knowledge of modern atomic theory and bonding to explain each of the following experimental observations. (Your explanations should be specific.) Refer to both substances when comparing. Within a family such as the alkaline earth metals, the ionic radius increases as the atomic number increases. The radius of the bromine atom is smaller than the radius of the bromide ion, Br-1. The first ionization energy of aluminum is lower than the first ionization energy of magnesium.
Answer:
(1) In the modern day periodic table the atomic size is increasing when we move down the group and it decreases when we move along the period from left to right. that's why Within a family such as the alkaline earth metals, the ionic radius increases as the atomic number increases. Alkaline earth metals have loosely held electrons which results in its increased size.
(2) The radius of the bromine atom is smaller than the radius of the bromide ion, Br-1 this happens because bromine is a non metal, and it also has a high electronegativity among other group elements as halogen group has high electronegativity. when the bromine acquires one extra electron and forms [tex]Br^-[/tex] ion, the configuration of bromine earlier was [tex]1s^22s^22p^63s^23p^64s^23d104p^5[/tex] but on addition of the electron the p shell will now have 6 electrons resulting in [tex]1s^22s^22p^63s^23p^64s^23d104p^6[/tex]the newly added electron repels the former neutral orientation and as a result of repulsion the size increases.
(3) The first ionization energy of Aluminum is lower than that of the first ionization energy of magnesium because magnesium has fully filled [tex]3s^2[/tex] orbital whereas Aluminum has one electron in the 3p orbitals, fully filled 3s orbitals has strongly held by the nucleus in case of Mg whereas 3p orbitals is shielded from the nucleus therefore it becomes easy to take out 3p electron that 3s electron.
PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP
DETERMINE THE MASS NUMBER OF EACH OF THE ISOTOPES OF LITHIUM
Answer:
not sure about it .I also need an answer