Answer:
Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.
Inventions: Periodic table, Pyrocollodion
Explanation:
*Hope this helps*
Answer:
Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.
Inventions: Periodic table, Pyrocollodion
Explanation:
What does a useful scientific explanation include ??
Answer: scientific explanation
Explanation:
A really good scientific explanation should do two main things: It should explain all the observations and data we have. It should allow us to make testable predictions that we can check using future experiments.
Law of Universal Gravitation (what factors affect gravity and how?)
Explanation:
Hey there!
According to the law of gravitation, the factors that affects the gravity are:
Mass of the heavenly bodies.Distance from the centre of the body to next body.Mass of heavenly bodies:The mass of heavenly bodies affect the gravity. We know that gravity is directly proportional to the mass of heavenly bodies. so, when the mass is more there is more gravity and where there is less mass there is less gravity.
Distance from the centre of the body to next body: It is one of the factor to influence gravity. When there is more distance there is less gravity and where there is distance more force is there. Is means gravity is inversely proportional to the distance between the bodies.
Hope it helps...
Uncontrolled energy:
causes destruction
produces order
can make things
can do useful work
Answer:
causes destruction
NEED HELP PLZ ASAP!!!!!
Im hvaing a hard time getting the right answer
1. If 2.49 g of CuNO3 is dissolved in water to make a 0.830 M solution, what is the volume of the solution in milliliters?
.01599 and 15.99 is wrong and I think Im doing the equation wrong, help!
Answer:
[tex]V=23.9mL[/tex]
Explanation:
Hello!
In this case for the solution you are given, we first use the mass to compute the moles of CuNO3:
[tex]n=2.49g*\frac{1mol}{125.55 g}=0.0198mol[/tex]
Next, knowing that the molarity has units of moles over liters, we can solve for volume as follows:
[tex]M=\frac{n}{V}\\\\V=\frac{n}{M}[/tex]
By plugging in the moles and molarity, we obtain:
[tex]V=\frac{0.0198mol}{0.830mol/L}=0.0239L[/tex]
Which in mL is:
[tex]V=0.0239L*\frac{1000mL}{1L}\\\\V=23.9mL[/tex]
Best regards!
Please help Fast I do not know
Answer:
So the answer to this question would be C. 400 J
Explanation:
Now for this problem, what is given is a 40 Newtons which would represent the force to be applied to the object, and a distance of 10 meters after the application of the said force. When these two combine, work is done. The unit for work is Joules and this is what we are looking for. The formula to get Joules or for work would be the force applied to the object multiplied by the distance that it travelled after the application of the force. It looks like this
work = force x distance
Joules = Newtons x meter
so let us substitute the variables to their corresponding places
Joules = 40 N x 10 m
Joules = 400 J
IF THIS HELPED YOU PLEASE MARK ME BRAINLIEST! THANKS! :)))))
explain the early theories of the atomic structure
Hi
i hope this helps
Answer:
The Greek atom theory
Explanation:
The concept of the Greek atomos theory is an indivisible particle of matter, goes back to ancient Greece and a man named Democritus held that all matter could be subdivided only until some finite particle was reached.
how dose dissolving sugar in water show that matter is made up of particles
Answer:
When sugar dissolves, the sugar particles separate from each other and mix with the water particles. When the sugar particles separate, the smaller water particles fit into the spaces between the larger sugar particles. The water and sugar particles are attracted to each other, so they move closer together when they mix.
Explanation:
: )
The Lewis diagram for BH2 is:
[H-B-H]-
The electron- pair geometry around the B atom in BH2 is:__________.
There are______lone pair(s) around the central atom, so the geometry of BH2 is________ .
Answer:
Electron pair geometry- trigonal planar
There is one lone pair around the boron atom
The geometry of BH2 is bent
Explanation:
The valence shell electron pair repulsion theory offers a frame work for determining the shape of molecules based on the number of electron pairs of the valence shell of the central atom in the molecule.
In BH2-, the central atom is boron. There is a lone pair on boron. Owing to the lone pair on boron, the molecular geometry of BH2 is bent.
The geometry of the electron pair around the Boron atom in [tex]BH_2[/tex] is called the trigonal planar. In this case, there is a pair of isolated electrons around Boron, which is the central atom, allowing the [tex]BH2[/tex] molecule to have a folded geometry.
We can arrive at this answer because:
Boron is an element that has three electrons in its valence layer.With this, we can find out that it can make three covalent bonds or donate these electrons to achieve chemical stability.In the case of the [tex]BH_2[/tex] molecule, boron forms covalent bonds with Hydrogen.These bonds allow the Hydrogens to be positioned on either side of the Boron molecule, forcing a pair of their electrons to focus on the center of that molecule, until it is attracted to the extremities.This allows for a folded geometry around the molecule, allowing Boron to be an exception to the octet rule and achieve stability with 5 electrons in the valence layer.
More information:
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. A student adds 50 mL of Lead (II) Nitrate solution to 50 mL of potassium iodide. Each
solution is colorless, but when these two liquids are mixed, a yellow precipitate is
observed. What has most likely happened in the experiment?
Answer:
after the reaction between Lead (II) Nitrate solution and potassium iodide occur Lead(II) iodide was formed and it's yellow color.
Explanation:
Pb(NO3)2 + KI = KNO3 + PbI2
How many hydrogen molecules are needed to produce two H2O molecules
Answer:
There are 2 Hydrogen molecules in H2O
Explanation:
if you look at the symbol for Hydrogen (H) you see that there is a number beside it, to the right. That number shows how many molecules there are of that element.
(Sidenote: If there is no number there is only one molecule)
Hope this helped :)
explain 5 the major innovation made from Abacus to the present fifth generation
Answer:
The major innovation made from Abacus to the present fifth generation is explained below in details.
Explanation:
Industrial Age - 1600
John Napier, a Scottish noble and diplomat consecrated much of his holiday time to the learning of mathematics. He was particularly engrossed in devising methods to aid estimates. His most famous offering was the discovery of logarithms. He listed logarithmic measures on a set of 10 board rods and thus was capable to do multiplication and division by equaling up numbers on the poles. These became recognized as Napier’s Bones.
which group or groups of atoms are the only atoms with f orbitals?
Answer:
Lanthanides and Actinides
Explanation:
In the reaction shown below, which substance is oxidized?
2Na + CuSO4 → Na2SO4 + Cu
A. Na
B. Na2SO4
C. Cu
D. CuSO4
Answer:
Na
Explanation:
Because sodium loses one electron and becons Na+ and sodium oxidizes
Los of electron is oxidation
Na is oxidised in the given reaction 2Na + CuSO[tex]_4[/tex] → Na[tex]_2[/tex]SO[tex]_4[/tex] + Cu. Therefore, the correct option is option A.
What is oxidation?When the oxidation state of either a molecule, atom, or ion increases, this is referred to as oxidation. The inverse process is termed reduction, and it happens when electrons are gained when the oxidation status of such an atom, molecule, as well as ion lowers.
When a chemical species oxidizes, its oxidation state rises. Oxidation does not always need the presence of oxygen! The phrase was first used when oxygen induced electron loss inside a process. The present definition is broader. Na is oxidised in the given reaction 2Na + CuSO[tex]_4[/tex] → Na[tex]_2[/tex]SO[tex]_4[/tex] + Cu.
Therefore, Na is oxidised in the given reaction 2Na + CuSO[tex]_4[/tex] → Na[tex]_2[/tex]SO[tex]_4[/tex] + Cu. The correct option is option A.
To learn more about oxidation, here:
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Which best defines a service? a task that is performed in exchange for payment an object that is acquired a plan that is executed an image that is drawn
Answer:
a task that is performed for payment
Explanation:
all of the other answers do not pertain to the question
A service is best defined as a task that is performed in exchange for payment.
What is a task?A task is an activity that needs to be accomplished within a defined period of time or by a deadline to work towards work-related goals, usually done in exchange for payment.
Thus, we can conclude that, a service is best defined as a task that is performed in exchange for payment.
Learn more about task here: https://brainly.com/question/12831236
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what does the phrase sea of electrons describe?? please help
Answer: Metallic Bonding.In metallic bonds, the valence electrons from the s and p orbitals of the interacting metal atoms delocalize. That is to say, instead of orbiting their respective metal atoms, they form a “sea” of electrons that surrounds the positively charged atomic nuclei of the interacting metal ions.
Explanation:
If I change the volume of a solution from 5.00 L to 10.0 L, what was the new
concentration if the original concentration was 4.0 M? Please help me as soon as possible with explanation.
The new concentration = 2 M
Further explanationDilution is a process of decreasing the concentration of a solution by adding a number of solvents
Can be formulated
M₁V₁=M₂V₂
M₁ = Initial Molarity
V₁ = Initial volume
M₂ = Final Molarity (after dilution)
V₂ = Final volume (after dilution)
V₁=5 L
V₂=10 L
M₁=4 M
The new concentration(M₂) :
[tex]\tt M_2=\dfrac{V_1.M_1}{V_2}\\\\M_2=\dfrac{5\times 4}{10}\\\\M_2=2~M[/tex]
Before we can use this equation for
calculations we must first balance it.
What whole number should be placed in the
green box to balance this equation?
2C2H6 + [? ]02 → [ ]CO2 + [ ]H20
Remember, the coefficients should be the
smallest whole numbers possible.
Answer:
2C₂H₆ + [7]O₂ → [4]CO₂ + [6]H₂O
Explanation:
Chemical equation:
C₂H₆ + O₂ → CO₂ + H₂O
Balanced chemical equation:
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
Step 1:
2C₂H₆ + O₂ → CO₂ + H₂O
Left hand side Right hand side
C = 4 C = 1
H = 12 H = 2
O = 2 O = 3
Step 2:
2C₂H₆ + O₂ → 4CO₂ + H₂O
Left hand side Right hand side
C = 4 C = 4
H = 12 H = 2
O = 2 O = 9
Step 3:
2C₂H₆ + O₂ → 4CO₂ + 6H₂O
Left hand side Right hand side
C = 4 C = 4
H = 12 H = 12
O = 2 O = 14
Step 4:
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
Left hand side Right hand side
C = 4 C = 4
H = 12 H = 12
O = 14 O = 14
The balanced equation for the syntheis of Iron (I) oxide is below:
If 5.4 moles of Fe react with 4.7 moles of O2, what is the maximum amount of Fe2O3 (in moles) that can be produced? What is the limiting reactant?
a
3.1 moles of Fe2O3 is the maximum amount that can be produced. Oxygen is the limiting reactant.
b
2.7 moles of Fe2O3 is the maximum amount that can be produced. Iron is the limiting reactant.
c
7.1 moles of Fe2O3 is the maximum amount that can be produced. Oxygen is the limiting reactant.
d
10.8 moles of Fe2O3 is the maximum amount that can be produced. Iron is the limiting reactant.
Answer:
Option B. 2.7 moles of Fe2O3 is the maximum amount that can be produced. Iron is the limiting reactant.
Explanation:
The balanced equation for the reaction is given below:
4Fe + 3O2 —> 2Fe2O3
From the balanced equation above,
4 moles of Fe reacted with 3 moles of O2 to produce 2 moles of Fe2O3.
Next, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
4 moles of Fe reacted with 3 moles of O2.
Therefore, 5.4 moles of Fe will react with = (5.4 × 3)/4 = 4.05 moles of O2.
Thus, we can see that only 4.05 moles out of 4.7 moles of O2 given is needed to react completely with 5.4 moles Fe. Therefore, Fe is the limiting reactant and O2 is the excess reactant.
Finally, we shall determine the maximum amount of Fe2O3 produced from the reaction.
In this case, the limiting reactant will be use because it will produce the maximum amount of Fe2O3 as all of it is used up in the reaction.
The limiting reactant is Fe and the maximum amount of Fe2O3 produced can be obtained as follow:
From the balanced equation above,
4 moles of Fe reacted to produce 2 moles of Fe2O3.
Therefore, 5.4 moles of Fe will react to produce = (5.4 × 2)/4 = 2.7 moles of Fe2O3.
Summary:
Limiting reactant => iron (Fe)
Maximum amount of Fe2O3 produce = 2.7 moles
trachea
Meaning of trachea
Answer:
The trachea, also called the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. The trachea is formed by a number of horseshoe-shaped rings, joined together vertically by ligaments over their substance and by the trachealis muscle at their ends. The epiglottis closes the opening to the larynx during swallowing.
Explanation:
You asked I answered.
Hope this helped! :)
P.S. If you still don't get where the trachea is, look at the graph below. :)
Which of these best describes the relationship between smoke from factories and acid
rain?
A
Smoke travels directly into clouds, creating acid rain.
B
Smoke turns clouds black, which causes them to become more acidic and release
black acid rain.
с
Smoke increases greenhouse gases, which make the water in clouds more acidic
so they release acid rain.
D
Smoke wipes out all the greenhouse gases in the atmosphere, increasing the
acidity of clouds so they create acid rain.
Answer:
I was about t ask the same question lol
Explanation:
Answer:
For flocabulary read and reaspond weather and erosion the answer is : C , i got the answer cause i got it wrong and i answered b so it is c
Explanation:
C is the correct answer
If you were to add glucose to catalase instead of hydrogen peroxide, would bubbles be produced?
Answer:
No, bubbles would not be produced.
Explanation:
Catalase is an enzyme that catalyses the decomposition of hydrogen peroxide into water (H2O) and oxygen gas (O2). Since oxygen (O2) is a gas, it is physically noticeable as BUBBLES. However, catalase as an enzyme is substrate-specific i.e. it solely acts/breaks down on hydrogen peroxide.
Hence, If one were to add glucose to catalase instead of hydrogen peroxide, oxygen gas observed as BUBBLES will not be produced because catalase will not act on glucose.
Potassium Phthalate, KC8H604, is a main source of whistle fuel for many fireworks. A standard firework had 25g of potassium phthalate. Calculate the following:
The molar mass of the compound.
How many molecules of fuel there are
The number of moles of Carbon
Answer:
Explanation:
The given compound is:
KC₈H₆O₄
Mass of the compound = 25g
Molar mass of the compound
KC₈H₆O₄
Atomic mass of K = 39
C = 12
H = 1
O = 16
Molar mass of the compound = 39 + 8(12) + 6 (1) + 4(16)
= 205g/mol
Number of molecules of fuel there in:
Find the number of moles then convert this to number of molecules;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Number of moles = [tex]\frac{25}{205}[/tex] = 0.12mol
1 mole of a compound contains 6.02 x 10²³ molecules
0.12 mole of the phthalate will contain 0.12 x 6.02 x 10²³ =
7.34 x 10²²molecules
Number of moles of Carbon
1 mole of the phthalate contains 8 mole of carbon
0.12 mole of the phthalate will contain 0.12 x 8 = 0.96mole of carbon
for each pair of compounds below , identify the one that would be expected to have more ionic character.explain you choice. (a)NaBr or HBr (b)BrCl or FCl
Answer:
a)NaBr
b)FCl
Explanation:
To identify which compound is more ionic we will calculate the electronegativity difference.
A) NaBr
Electronegativity of Na = 0.93
Electronegativity of Br = 2.96
Electronegativity difference = 2.96- 0.93 = 2.03
HBr
Electronegativity of H = 2.2
Electronegativity of Br = 2.96
Electronegativity difference = 2.96 - 2.2 = 0.76
NaBr have more ionic character because of large electronegativity difference.
B) BrCl
Electronegativity of Cl = 3.16
Electronegativity of Br = 2.96
Electronegativity difference = 3.16 - 2.96 = 0.2
FCl
Electronegativity of F = 3.98
Electronegativity of Br = 2.96
Electronegativity difference = 3.98 - 2.96 = 1.02
FCl have more ionic character because of large electronegativity difference.
Melting can be best described as a process in which molecules?
Answer:
... lose kinetic energy and move slowly.
Melting can be best described as a process in which molecules gain enough kinetic energy to get past each other.
Scientists use _____ as chemical symbols.
dots
letters
shapes
lines
Answer:
Letters
Explanation:
Answer:
Letters
Explanation:
Chemical symbols are used to standardize the 'language of chemistry' and to identify elements and atoms in a chemical formula easily. Chemical symbols consist of one or two letters, most often derived from the name of the element.
Help me if you know this pleaseeee
Answer:
help you with what?
Explanation:
What are the coefficients for the reaction _Cl2O5 + _H2O → _HClO3 once it is balanced?
1, 1, 1
1, 1, 2
1, 2, 2
2, 1, 1
Answer:
1, 1, 2
Explanation:
Answer:
Answer is B. 1, 1, 2
Explanation:
<3
middle school science help please
Answer:
The answer is 'All of the above'
Explanation:
because the hydrogen ions are represented by the symbol H+, they increase the PH value of a solution if less amount is added but they decrease the PH value of a solution if a larger amount of hydrogen ions are added but still they increase the PH value, and of course, they contribute to a solution by a base.
Answer:
Hydrogen ions are represented by H+.
Explanation:
Hydrogen ions usually decreases the pH value when added to a solution.Hydrogen ions are contributed to a solution by a acid.
What is electronegativity?
Explain the periodic trend -
what is it, why is it that way
Answer:
Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used. Fluorine (the most electronegative element) is assigned a value of 4.0, and values range down to caesium and francium which are the least electronegative at 0.7.
Explanation:
Major periodic trends include: electronegativity, ionization energy, electron affinity, atomic radius, melting point, and metallic character. ... These trends exist because of the similar atomic structure of the elements within their respective group families or periods, and because of the periodic nature of the elements