Answer:
chemistry - the science that studies the properties of substances and natural fenomens .
...........
Answer:
The Basic definition of Chemistry is:-
Chemistry is the scientific study of the properties and behavior of matter. It is the natural science that covers the elements that make up matter to the compounds that is composed of atoms, molecules and ions.
A student in a lab holds an iron nail over an open flame, and no reaction occurs. The nail is then filed, creating small pieces of
iron shavings. These pieces burn brightly when placed over an open flame.
Which statement accurately identifies one of the changes that occurs as a physical or chemical change?
Formation of small pieces of iron shavings is a physical change whereas burning of pieces of iron shavings is chemical change.
Formation of small pieces of iron shavings is an example of physical change because it can be changed again into nail while on the other hand, burning of pieces of iron shavings on the flame is an example of chemical change because it can't change again into its original shape. Physical change is a change in matter which does not change the chemical properties of the matter whereas chemical change is a change in matter which change the chemical properties of the matter.
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Tìm hóa trị của Fe trong hợp chất : FESO4, FE2(SO4)3, FR(OH)2, FE(OH)3
Answer: Fe hóa trị II trong các hợp chất: FeSO4, Fe(OH)2
Fe hóa trị III trong các hợp chất: Fe2(SO4)3, Fe(OH)3
Explanation:
¿Qué ocurre cuando la radiación del sol atraviesa la atmósfera?
La luz es la fuente de energía y radiación que recibe la Tierra desde el espacio. De toda la energía que entra a la atmósfera una parte es absorbida y otra reflejada. Tanto el aire con sus partículas y moléculas gaseosas como la superficie terrestre (suelo, ciudades, bosques, mares, hielo, etc.) absorben y reflejan en diferente proporción la energía radiante entrante.
Asumiendo, que al tope (última capa) de la atmósfera llega un 100% de la radiación solar, de este total, un 20% es absorbido por las nubes y gases atmosféricos, pero también la atmósfera refleja al espacio un 6%, las nubes reflejan un 20% y el suelo refleja un 4%. El porcentaje de energía restante es absorbida por la superficie de la Tierra (¿cuánto es?).
4. Representar gráficamente los valores y la dirección de las energías radiantes absorbidas y reflejadas a partir de un valor total de energía solar entrante a la atmósfera igual al número de la suma de su fecha de nacimiento asignada previamente en unidades de vatios por cada metro cuadrado (W/m2).
Ejemplo: energía solar entrante = 2.026 W/m2
Asuma que a la atmósfera llega un 100% de la radiación solar (el valor corresponde a la suma de su fecha de nacimiento), de este total, un 20% es absorbido por las nubes y gases atmosféricos, pero también la atmósfera refleja al espacio un 6%, las nubes reflejan un 20% y el suelo refleja un 4%. El porcentaje de energía restante es absorbida por la superficie de la Tierra (¿cuánto es?).
Can someone help me please
Ribbon diagrams shows secondary structures and appear less detailed than other model types. In one to two sentences, give a reason the chemists would use ribbon diagrams. What type of information do they provide?
Answer:
They show helixes and proteins
Explanation:
Ribbon diagrams are the Richardson diagrams that represent the protein structures. Chemist prefers using Ribbon diagrams to show the various structure of the proteins.
What are ribbon diagrams?The Ribbon diagram is used to represent the structural organization of the protein in the polypeptide chains or individually. It shows the three-dimensional structure and organization of the protein framework.
The ribbon diagram for the secondary structure of the protein shows the intramolecular and intermolecular structure along with helixes and bonding. It shows the detailed structure of the protein organization including the helix and sheets.
Therefore, the ribbon diagram is used by chemists to determine the structure of the protein as they give the details about the helix and sheet.
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How Chemistry and Earth Science are Connected?Can you tell me completely?
Explanation:
Because chemistry deals with the structure of matter (such as the structure of the atom, it is related to physics. ... Because geology involves study of the matter the Earth and other bodies in the solar system are made of, geology involves chemistry. Geochemistry is the study of Earth materials, and how they change.
What is the order, plz answer
Answer:
C A B
Explanation:
come on, you also know this from normal water waves.
which ones are stronger (= have more energy) ? the small ones or the big ones ?
and the same applies to all waves. the bigger the waves (higher amplitude), the more energy.
what charge does an atom that has lost electrons have?
Answer:
when an atom loses electrons, it will then contain more protons. Thus, the charge of the atom become positive.
What name is given to a metal when it forms an ion, and what type of charge does it have?
Answer:
Cation metal. Positive charge.
Answer:
DHS has been working hard for years and it is still unclear whether this would happen if it is to end the market with the engine is a little less than the next 5years to be 8years in the first quarter and the same year in a quarter or less than a quarter or more than that
number of moles from the formula is multiplied by the atomic mass of each _______, and then all those masses are added together.
A)
atom
B)
particle
C)
molecule
D)
electron
Answer:
D. electron
Explanation:
What happens when acetylene reacts with silver powder?
explain the importance of measurement in our daily life
full form of soil pH
Answer:
PH STANDS FOR POTENTIAL OF HYDROGEN .
It represents the ratio of Hydronium ions (H3O) to Hydroxide ions (OH). It is a measure of acidity and alkalinity of a solution.
FOLLOW MEConvert 16.7 inches to yards (there are 3 feet in a yard)
Using the method of dimensional analysis
Answer:
Explanation:
16.7 inches [1 foot / 12 inches] [1 yard / 3 feet] Notice how the units cancel each other out. You do have numbers in the denominator. What you get, looks like this
16.7
------
(12 * 3)
16.7 / 36
0.4639 yrds
It is often possible to change a hydrate into an anhydrous compound by heating it to drive off the water (dehydration). A 43.19 gram sample of a hydrate of MgBr2 was heated thoroughly in a porcelain crucible, until its weight remained constant. After heating, 27.21 grams of the anhydrous compound remained. What is the formula of the hydrate?
Answer:
[tex]\rm MgBr_2 \cdot 6\, H_2O[/tex].
Explanation:
Let [tex]x[/tex] denote the number of [tex]\rm H_{2}O[/tex] formula units for every [tex]\rm MgCl_{2}[/tex] formula unit. The formula of the hydrate would be [tex]{\rm MgBr_2} \cdot x\, {\rm H_2O}[/tex].
Look up the relative atomic mass of each element on a modern periodic table:
[tex]\rm Mg[/tex]: [tex]24.305[/tex].[tex]\rm Br[/tex]: [tex]79.904[/tex].[tex]\rm H[/tex]: [tex]1.008[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].Formula mass:
[tex]\begin{aligned}M({\rm MgBr_{2}}) &= 24.305 + 2 \times 79.904 \\ &= 184.113\; \rm g\cdot mol^{-1}\end{aligned}[/tex].
[tex]\begin{aligned}M({\rm H_{2}O}) &= 2 \times 1.008 + 15.999 \\ &= 18.015\; \rm g\cdot mol^{-1}\end{aligned}[/tex].
The anhydrous compound would be [tex]\rm MgBr_{2}[/tex]. There was [tex]27.21\; \rm g[/tex] of this compound. Calculate the number of moles of formula units in that much of this compound:
[tex]\begin{aligned}n({\rm MgBr_{2}}) &= \frac{m({\rm MgBr_{2}})}{M({\rm MgBr_{2}})} \\ &= \frac{27.21\; \rm g}{184.113\; \rm g \cdot mol^{-1}} \\ &\approx 0.1478\; \rm mol\end{aligned}[/tex].
During heating, [tex]43.19\; \rm g - 27.21\; \rm g = 15.98\; \rm g[/tex] of water [tex]\rm H_{2}O[/tex] escaped from the hydrate. Calculate the number of formula units in that [tex]15.98\; \rm g[/tex] of [tex]\rm H_{2}O\![/tex]:
[tex]\begin{aligned}n({\rm H_{2}O}) &= \frac{m({\rm H_{2}O})}{M({\rm H_{2}O})} \\ &=\frac{43.19\; \rm g - 27.21\; \rm g}{18.015\; \rm g \cdot mol^{-1}} \\&= \frac{15.98\; \rm g}{18.015\; \rm g \cdot mol^{-1}} \\ &\approx 0.887\; \rm mol\end{aligned}[/tex].
In other words, approximately [tex]0.1478\; \rm mol[/tex] of [tex]\rm MgBr_{2}[/tex] formula units (and hence the same number of moles of [tex]{\rm MgBr_2} \cdot x\, {\rm H_2O}[/tex] formula units) contain approximately [tex]0.887\; \rm mol[/tex] of [tex]\rm H_{2}O[/tex] formula units. Calculate the ratio between the two:
[tex]\begin{aligned}x &= \frac{n({\rm H_{2}O})}{n({\rm MgBr_2})} \\ &\approx \frac{0.1478\; \rm mol}{0.887\; \rm mol} \approx 6\end{aligned}[/tex].
Hence, the formula of the hydrate would be [tex]\rm MgBr_2 \cdot 6\, H_2O[/tex].
Identify what type of reaction is taking place:
CH3CH3 + Br2 -> CH3Br + HBr
A. Addition
B. Fermentation
C. Substitution
D. Elimination
3. How can you decrease the pressure of a gas in a container without changing the volume of the gas?
add more gas particles to the container
move the container to a lower altitude
o o
reduce the temperature of the gas
O
change the shape of the container
Answer:
reduce the temperature of the gas
Explanation:
when you reduce the temperature of the gas the pressure will decrease
Which of the following pairs of compounds have the same empirical formula?
a. acetylene, C2H2, and benzene, C6H6
b. ethane, C2H6, and butane, C4H10
c. nitrogen dioxide, NO2, and dinitrogen tetroxide, N2O4
d. diphenyl ether, C12H10O, and phenol, C6H5OH
Answer:
option a and c both are correct
Explanation:
please mark me as brainliest
The pairs of compounds have the same empirical formula are:
a. acetylene, C₂H₂, and benzene, C₆H₆ and
c .nitrogen dioxide, NO₂, and di nitrogen tetroxide, N₂O₄
What is empirical formula?The empirical formula of a compound is defined as the formula that shows the ratio of elements present in the compound, but not the actual numbers of atoms found in the molecule.
In some cases, the empirical formula is the same as the molecular formula, which gives the actual number of atoms in a compound (e.g., H₂O).Otherwise, the molecular formula is a multiple of the empirical formula (e.g., CH₂O is the empirical formula for glucose, C₆H₁₂O₆).
Examples of empirical formulas:
Glucose has a molecular formula of C₆H₁₂O₆. It contains 2 moles of hydrogen for every mole of carbon and oxygen. The empirical formula for glucose is CH₂O.
The molecular formula of ribose is C₅H₁₀O₅, which can be reduced to the empirical formula CH₂O.
The pair with empirical formula is acetylene, C₂H₂, and benzene, C₆H₆ and
nitrogen dioxide, NO₂, and di nitrogen tetroxide, N₂O₄
Thus, option (A) and (C) are correct.
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During a lab experiment performed at STP conditions, you prepare HCl by reacting 100. ml of Cl2 gas with an excess of H2 gas.
How many ml of a solution of Ba(OH)2 0.230M do you need to neutralize all the HCl produced?
Answer: 19.4 mL Ba(OH)2
Explanation:
H2(g) + Cl2(g) --> 2HCl(aq) (make sure this equation is balanced first)
At STP, 1 mol gas = 22.4 L gas. Use this conversion factor to convert the 100. mL of Cl2 to moles.
0.100 L Cl2 • (1 mol / 22.4 L) = 0.00446 mol Cl2
Use the mole ratio of 2 mol HCl for every 1 mol Cl2 to find moles of HCl produced.
0.00446 mol Cl2 • (2 mol HCl / 1 mol Cl2) = 0.00892 mol HCl
HCl is a strong acid and Ba(OH)2 is a strong base so both will completely ionize to release H+ and OH- respectively. You need 0.00892 mol OH- to neutralize all of the HCl. Note that one mole of Ba(OH)2 contains 2 moles of OH-.
0.00892 mol OH- • (1 mol Ba(OH)2 / 2 mol OH-) • (1 L Ba(OH)2 / 0.230 M Ba(OH)2) = 0.0194 L = 19.4 mL Ba(OH)2
Light energy is part of a larger form of energy known as
A. Chemical energy
B. Nuclear energy
C. Electromagnetic energy
D. Elastic energy
Answer:
C. Electromagnetic energy
Explanation:
Light energy is part of a larger form of energy known as "Electromagnetic energy"
What is light energy?
The ability to produce different types of light observable to human sight makes light energy a kind of kinetic energy. A heated object such as a laser, a lightbulb, or the sun emits electromagnetic radiation, which is referred to as light. Photons, which were tiny energy packets, were present in light.
What is Electromagnetic energy?An electromagnetic energy could be used to describe or model light. According to this hypothesis, a shifting magnetic field is produced by a shifting electric field. Then, as the magnetic field changes, the electric field also changes.
Light energy is part of a larger form of energy known as "Electromagnetic energy"
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An ionic bond is between which two types of elements?
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal. A covalent bond involves a pair of electrons being shared between atoms.
question 3 chemistry help
ca and o is one ca s is two and the other one is s and o
[tex]v=0.164m*8.3cm*12.4cm[/tex]
Answer:
helloooo
0.164m * 100 = 16.4 cm
now multiplying all of em
v = 1,687.888
If you started with 2 moles of Nitrogen and 3 moles of Hydrogen, then you
would not have any leftover reactants. Explain which material would be
limiting since no hydrogen or nitrogen were left over?
N2 + 3H2 -> 2NH3
Answer: 0.3 moles NH3
Explanation:
question 8 chemistry help
Answer:
Sorry,I can't do this because i don't know this questions answer.
describe how thin layer chromatography is used in the isolation and extraction of lipids
Thin layer chromatography(TLC) works with the principle of separation through adsorption.
It is used in the isolation and extraction of lipids through the following steps:
apply the lipid samples spots in the bottom of the plate.also apply sample solution to the marked spotpour the mobile phase into the TLC chamber and use a moist filter paper to cover it. this is done to maintain equal humidity.then place the plate in the TLC chamber and close it with a lid.the plate is immersed into the solvent (mobile phase) for its development. this is done, keeping in mind that the sample spot should be above the solvent.once the sample spots are developed, they are removed and dried.this is later viewed using the UV light chamber to see the isolation of the lipid sample.Learn more here:
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.) What happens when Carbon dioxide gas is Collected down ward of water ?
when carbon dioxide gas is collected down ward of water wet gas is collected by the downward displacement of water . This is used for gases that are not very soluble in water . ... In water , carbon dioxide produces a weakly acidic solution , carbonic acid .
PLZ HELP ME A girl throws a ball and her dog chases it. What characteristic of living things is this dog demonstrating as it chases the ball?
A. Cells
B. Reproduction
C. Growth
D. Response
A student conducts an experiment to determine how the temperature of water affects the time for sugar to dissolve. In each trial, the student uses a different amount of water and a different temperature of water. What is wrong with this experimental design? A.The student changed more than one independent variable. B.The student did not change enough independent variables. C.The student needs to perform more trials. D.The student does not have a dependent variable.
What is wrong with the experimental design is that the student changed more than one independent variable.
WHAT AN EXPERIMENT SHOULD CONTAIN?
An experiment is a procedural method of solving a scientific problem or answering a scientific question. An ideal experiment should contain two variables namely: independent variable and dependent variable. Dependent variable: This is the variable that the experimenter measures in the experiment. The dependent variable responds to changes made to the independent variable. Independent variable: This is the variable that is manipulated in an experiment in order to bring about a response.In the experiment conducted by the student in this question in order to determine how the temperature of water affects the time for sugar to dissolve. The independent variable is the DIFFERENT TEMPERATURE OF WATER while the dependent variable is the TIME TAKEN FOR SUGAR TO DISSOLVE.
N.B: An experiment should have only one independent variable and all other variables should be kept constant. This is to have a reliable result.
However, this student used two independent variables (temperature and amount of water) for the experiment, which is wrong for the experimental design.Therefore, the fact that the student changed more than one independent variable is wrong for the experimental design.
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Answer:
The student changed too many variables.
Explanation:
in k-12 took the quiz
If we shake the branches of the tree the fruits fall.why?
Answer:
When we shake the branch of a tree the tree possesses a state of motion whereas the fruits and leaves tend to remain in state of rest. Due to this inertia of rest the fruits and leaves get detached from the branch and because of gravity it falls down.
Explanation:
so it's because of the gravity .
