Answer:
The correct answer is C. Plz mark brainiest
Explanation:
Calculate the mass (in grams) of hydrogen gas produced when 33.61 g of
diborane (B2H) reacts with excess water.
B Holg) + 6H2O(1)→ 2 H3B03(s) + 6H2(g)
Only enter numerical value without units.
Answer:
14.40g of H2
Explanation:
The balanced equation for the reaction is given below:
B2H6(g) + 6H2O(l) → 2H3BO3(s) + 6H2(g)
Next, we shall determine the mass of B2H6 that reacted and the mass of H2 produced from the balanced equation. This is illustrated below:
Molar mass of B2H6 = (2x11) + (6x1) = 28g/mol
Mass of B2H6 from the balanced equation = 1 x 28 = 28g
Molar mass of H2 = 2x1 = 2g/mol
Mass of H2 from the balanced equation = 6 x 2 = 12g
From the balanced equation above,
28g of B2H6 reacted to produce 12g of H2.
Finally, we shall determine the mass of H2 produced when 33.61g of B2H6 reacted with excess water. This can be obtained as follow:
From the balanced equation above,
28g of B2H6 reacted to produce 12g of H2.
Therefore, 33.61g of B2H6 will react to produce = (33.61 x 12)/28 = 14.40g of H2.
Therefore, 14.40g of H2 were produced from the reaction.
1.1 The elements with the lowest ionization energy of all element are
O The noble gases
O The alkali metals
O The alkaline earth metals
O The halogens
Answer:
O The alkali metalsThe elements with the lowest ionization energy of all element are alakli metals
Explanation:
According to research,
The element with the lowest ionization energy is cesium (Cs). Cesium has atomic number 55 and is in the fifth row of the periodic table.
Caesium is a soft, silvery-golden alkali metal .
Which will a positively charged object attract? an object that has a negative charge an object that has a smaller positive charge an object that has no charge an object that has a larger positive charge
Answer:
it will attract an object that has a negative charge
Positively charged objects will attract negatively charged objects.
Law of magnetic attractionsAccording to the law "like charges repel, unlike charges attract', a positively charged substance will repel other positively charged substances.
On the other hand, a positively charged substance will attract every other substance that is negatively charged.
More on the law of magnetic attraction can be found here: https://brainly.com/question/8515415
Which of the following chemical reactions is reversible?
A. The burning of wood.
OB. The dehydration of copper sulfate (CuSO4).
O C. The neutralization of an acid.
OD. The freezing of water into ice
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how many dots would go around xenon in electron dot diagram
Answer:
8
Explanation:
Since Xe (xenon) is a noble gas, it has 8 valence electrons. It's outer shell is full and it is a stable element and doesn't like to react. Therefore, since the electron dot diagram is about valence electrons, 8 would be your answer.
1. Find the volume ( cm3) of oxygen in: a. 1000cm3 of air b. 50 cm3 of air.
Answer:
A. 210 cm³
B. 10.5 cm³
Explanation:
It is important for us to note that air contains 21% of oxygen, O2. With this idea in mind, let us answer the questions given above.
A. Volume of air = 1000 cm³
Volume of O2 in air =.?
Percentage composition of O2 in air = 21%
Volume of O2 = 21% x 1000
Volume of O2 = 21/100 x 1000
Volume of O2 = 210 cm³
Therefore, the volume of O2 in 1000 cm³ of air is 210 cm³.
B. Volume of air = 50 cm³
Volume of O2 in air =.?
Percentage composition of O2 in air = 21%
Volume of O2 = 21% x 50
Volume of O2 = 21/100 x 50
Volume of O2 = 10.5 cm³
Therefore, the volume of O2 in 50 cm³ of air is 10.5 cm³.
Determine the new pressure of a sample of hydrogen gas if the volume and moles are constant, the initial pressure is 6.0 atm, and it is heated from 15°C to 30.°C. PLEASE HELP ASAP! THANK U SO MUCH!
6.3 atm
5.7 atm
12 atm
3.0 atm
Answer:
6.3 atm.
Explanation:
Data obtained from the question include:
Initial pressure (P1) = 6 atm
Initial temperature (T1) = 15°C = 15°C + 273 = 288K
Final temperature (T2) = 30°C = 30°C + 273 = 303K
Final pressure (P2) =..?
Since the volume and number of mole of the hydrogen gas sample is constant, the following equation will used to obtain the new pressure:
P1/T1 = P2/T2
6/288 = P2 /303
Cross multiply
288 x P2 = 6 x 303
Divide both side by 288
P2 = (6 x 303) /288
P2 = 6.3 atm
Therefore, the new pressure of the hydrogen gas sample is 6.3 atm.
seasonal variation in Earth's climate are caused by
a Earth's rotation
b Earth's tilt
c Earth's magnetic field
d Earth's precession
Answer: B: Earths tilt
Explanation:
Seasonal variation occurs because the Earth is tilted on its axis by 23.5˚. As Earth orbits the sun, its orientation to the sun changes.
Drag each label to the correct location. Match the climate zones to their relative temperature levels. (coldest zonehottest zonemoderate temperature zone)
Answer:
Polar Zones - Coldest Temperature
Temperate Zones - Moderate Temperature
Tropical Zones - Hottest Temperature
Explanation:
The closer you are to the Equator, the hotter it gets, as the sun hits the middle of the Earth the most. At the poles, the sun hits it there the least, so it is the coldest. In between, we would have a mild between hot and cold.
*Remember that the Earth is at a tilt, and that is why we have seasons and why the Equator is so hot and the Poles are so cold.
Answer:
I answered the question on edmentum and that person was correct.
Explanation:
The polar zone is the coldest because the Sun’s rays hit this part of Earth at a wide angle, causing their energy to be spread thinly over a large surface area.
The topical zone is the hottest because the Sun’s rays hit this part of Earth nearly straight on, focusing the heat on a small surface area.
The temperate zone experiences moderate temperatures because the Sun’s rays hit this zone at an angle that concentrates the heat on a surface area that is smaller than on the polar zone and larger than on the tropical zone.
The kinetic-molecular theory of gases says A. the particles of a gas move independently of each other. B. the particles in a gas move rapidly. C. the particles in a gas are far apart. D. all of the above.
Answer:
D. all of the above.
Explanation:
The kinetic-molecular theory of gases suggests that; the particles of a gas move independently of each other, the particles in a gas move rapidly, the particles in a gas are far apart.
Hope it helps.
14.
Two jewelers were asked to measure the
mass of a gold nugget. The true mass of the
nugget is 0.856 grams (g). Each jeweler took
three measurements. The average of the
three measurements was reported as the
"official” measurement with the following
results:
Jeweler A: 0.863 g, 0.869 g, 0.859 g
Jeweler B: 0.875 g, 0.834 g, 0.858 g
Which jeweler's official measurement was
more accurate? Which jeweler's measure-
ments were more precise? In each case, what
was the error and percent error in the official
measurement?
Answer:
Jeweler B = more accurate
Jeweler A = more precise
Error:
0.008, 0
% error :
0.934% ; 0
Explanation:
Given that:
True mass of nugget = 0.856
Jeweler A: 0.863 g, 0.869 g, 0.859 g
Jeweler B: 0.875 g, 0.834 g, 0.858 g
Official measurement (A) = 0.863 + 0.869 + 0.859 = 2.591 / 3 = 0.864
Official measurement (B) = 0.875 + 0.834 + 0.858 = 2.567 / 3 = 0.8556
Accuracy = closeness of a measurement to the true value
Accuracy = true value - official measurement
Jeweler A's accuracy :
0.856 - 0.864 = - 0.008
Jeweler B's accuracy :
0.856 - 0.856 = 0.00
Therefore, Jeweler B's official measurement is more accurate as it is more close to the true value of the gold nugget.
However, Jeweler A's official measurement is more precise as each Jeweler A's measurement are closer to one another than Jeweler B's measurement which are more spread out.
Error:
Jeweler A's error :
0.864 - 0.856 = 0.008
% error =( error / true value) × 100
% error = (0.008/0.856) × 100% = 0.934%
Jeweler B's error :
0.856 - 0.856 = 0 ( since the official measurement as been rounded to match the decimal representation of the true value)
% error = 0%
Scientific evidence shows that Earth's diameter, and thus overall size, does.
not change. This evidence goes against which two theories?
A. Expanding Earth
B. Plate tectonics
U
C. Contracting Earth
D. Continental drift
SUBMIT
Answer:
Expanding earth and contracting earth
Explanation:
Answer:
A and C
Explanation:
Which of the measurement contain three significant figure?
Answer:
The answer is explained below
Explanation:
The question is not complete.
The correct question should be like:
Which of the measurement contain three significant figure?
500
395
0.001
0.00100
1 × 10⁻³
5 × 10²
Answer:
The following are rules applied when considering significant figures:
i) All digits are significant excluding zero. E.g of significant digits are 1,2,3,4,5,6,7,8,9
ii) Any zero that appear within or after non zero digits are significant e.g. 200, 1004, 500009
iii) Zeros before non zero digits are not significant. An example shows significant digits bolded 001, 0.0012, 001.56
iv) Zeros that come after non zero digits are significant even if the number is in decimal form. An example shows significant digits bolded 1000, 0.001200, 001.5600
Therefore:
500: It contains three significant digits
395: It contains three significant digits
0.001: It contains only one significant digits
0.00100: It contains three significant digits
1 × 10⁻³: 1 × 10⁻³ = 0.001. It contains only one significant digits
5 × 10²: 5 × 10² = 500. It contains three significant digits
The measurements that contain three significant figure are 500, 395, 0.00100 and 5 × 10²
What type of nuclear decay is shown by the reaction below?
2390 → He + 23% Th
O A. Fusion
B. Alpha
C. Beta
D. Gamma
Answer:
B. Alpha
Explanation:
Alpha decays always split into an element and He.
Beta decays always split into an element and e- (eletrons).
Gamma decays always split into an element and radiation.
Bird wings and dragonfly wings are both used for flight.
Answer:
Yes
Explanation:
What's the question?
Answer:
yes, they both use it to fllight.
Explanation:
As they are adapted to flight to various places to catch their prey and be safe from various type of harms.
hope it helps..
PLEASE HELP!
Why is phosphorus diamagnetic.
Answer:
FROM the magnetic point of view, phosphorus is an extremely interesting
substance because of its allotropic modifications. The ordinary forms are
the yellow (or white) and the red varieties. X-ray investigations indicate
that probably yellow phosphorus is analogous with the cubic forms of antimony and arsenic; and red phosphorus with monoclinic antimony and
arsenic (Mellor, 1928). The conclusions of different workers on the structure of red phosphorus are not in agreement. There is also Bridgman's black
phosphorus which is probably hexagonal (Linck and lung, 1925). Natta
and Passerini (1930) have studied the crystal structure of white phosphorus.
This substance when condensed at the temperature of liquid ammonia is
cubic. Atomic positions however are yet undetermined. Another and noncubic form is obtained by condensation at liquid-air temperatures. It is
thus clear that most likely white phosphorus is cubic in structure with a
probable superposition of another lattice.
The evidence from Raman effect also points to the same conclusion.
Bhagavantam (1930) investigated the Raman effect of white phosphorus in
the solid state. The characteristic frequencies obtained by him are 607, 468
and 374. Since the phosphorus molecule is known to contain 4 atoms,
Bhagavantam (1930) has shown that the tetrahedral structure fits the results
satisfactorily since such a structure would give only three frequencies. But
for the particular law of forces adopted, the frequencies should have the
ratio 2: 2: 1 but the observed frequencies deviate considerably.
Phosphorus is a really intriguing element. because of the allotropic changes to the material.
Why phosphorus is dimagnetic?Red phosphorus is likely akin to monoclinic antimony, while yellow phosphorus is probably similar to the cubic forms of antimony and arsenic.
There is disagreement among the findings of many researchers regarding the structure of red phosphorus. Additionally, Bridgman's black It is presumably hexagonal, phosphorous (Linck and lung, 1925). Natta and Passerini (1930) have investigated the white phosphorus crystal structure.
Condensed from this material at liquid ammonia temperature is cubic. However, the locations of the atoms are still unknown. Condensation at liquid air temperatures yields a different, noncubic shape.
Therefore, Phosphorus is a really intriguing element. because of the allotropic changes to the material.
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The products of a reaction are NaCl and H2O. What does the law of conservation of matter reveal about the reactants in the reaction? A. At least some of the reactants will include NaCl and H2O. B. The reactants will contain only Na, Cl, O, and H in some amounts. C. Na, Cl, O, H, and three other elements were the reactant elements. D. The reactants will have one Na, one Cl, one O, and two H atoms.
Answer:
D
Explanation:
total mass should be equal on both sides
it's a double do displacement reaction
HCl + NaOH --> NaCl + H2O
4. Which change to a DNA molecule would have the least effect on an organism?
A: an addition to a base sequence at the beginning of a gene
B: a substitution in a base sequence that does not code for a protein
C: a substitution that creates a "stop" code in the middle of a gene
D: a deletion from a base sequence in the middle of a gene
Answer: Change in a single nitrogen base in the DNA sequence will not have any significant effect on the organism.
So A
Explanation:
This is known as point mutation and it does not have any significant change in the protein and it is least harmful type of DNA mutation.
9. A bond formed between a silicon atom and an oxygen atom is likely to be
O polar covalent
O coordinate covalent
O ionic
O nonpolar covalent
The answer is
O ionic
Explanation:
A bond formed between a silicon atom and an oxygen atom is likely to be: ionic
Answer: Polar covalent
Explanation: Gradpoint
PLEASE HELP! Write the full electron configuration for phosphorus, atomic symbol P, then draw an orbital box diagram that accounts for all of the electrons in phosphorus. You don’t need to include the orbital box diagram as part of your answer. Based on your drawing, explain why phosphorus is either paramagnetic or diamagnetic.
Answer:
1) The full electron configuration for phosphorus is 1s²2s²2p⁶3s²3p
2) Phosphorus is paramagnetic
Explanation:
1) To write the electron configuration, we follow the electron filling order, that is starting from 1s, to 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4f, 5s, 5p, 5d, 6s till the electrons are all accounted for (up to 58)
We note that the s orbitals can each take two electrons while the p orbital can take 6 electrons and the d orbital can take 10 electrons
The electron configuration chart for phosphorus, P, is given as follows;
1s²2s²2p⁶3s²3p.
2) Diamagnetism is the temporary magnetism is the magnetism of a material that exists in the presence of a magnetic field due to a a change in the atomic electron orbital motion
Paramagnetism is a magnetism in which a material is weakly attracted by an applied external magnetic field such that there is induced magnetism in the applied magnetic field direction
Paramagnetic materials have have unpaired electrons that give them permanent magnetic moments in the absence of an applied magnetic field as such unpaired electrons are termed paramagnetic electrons and atoms that have one or more unpaired electrons are paramagnetic
Phosphorus, with the 3 partially filled p orbitals have 3 unpaired electrons in their outermost shell giving them the overall properties of a paramagnetic materials.
Which answer below correctly identifies the type of change and the explanation for the boiling of water?
o physical change because even though the change caused the temperature of the water to
increase, the water's physical properties remained exactly the same
o physical change because even though gas formation was observed, the water was undergoing a
state change, which means that its original properties are preserved
chemical change because gas formation was observed, which indicated that the water was
transformed into a different substance
O chemical change because a temperature change was observed, which indicated that the water
was transformed into a different substance
Answer:
O chemical change because a temperature change was observed, which indicated that the water
Explanation:
I have taken this class
To draw a Lewis structure for a polyatomic ion, begin by calculating A, the available electrons, and N, the needed electrons. What is N for CIO3-, the chlorate ion?
Answer:
N for chlorate ion is one
Explanation:
Because N is the number of electrons needed to form octet structure causing a negative charge of one, since it already has 25valence electrons
Answer: 26
Correct Answer
Which compound is used to make asphalt? a saturated hydrocarbon that has more than 35 carbons in its chain a saturated hydrocarbon that has between 17 and 35 carbons in its chain a saturated hydrocarbon that has between 5 and 8 carbons in its chain a saturated hydrocarbon that has between 1 and 2 carbons in its chain
Answer:
answer is A. a saturated hydrocarbon that has more than 35 carbons in its chain
Explanation:
edge in 2020 :)
The compound which is used to make asphalt is a saturated hydrocarbon that has more than 35 carbons in its chain.
What is asphalt?Asphalt is also known by the name of bitumen, its appearance is sticky and black or present in semi solid form of petroleum.
Asphalt is a kind of hydrocarbon means mainly formed by the composition of carbon atoms and hydrogen atoms, but in very trace quantity amount of nitrogen, sulfur and other hateroatoms are also present. It is present in complex form means both saturated and unsaturated or aliphatic and aromatic compounds are present in it. It is formed by the long carbon chain which has a number of Carbon atoms around 150.
Hence it is a saturated hydrocarbon that has more than 35 carbons.
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Which best explains why a firework being ignited is an example of an exothermic reaction and not an endothermic reaction?
A)The fireworks produce colors.
B)The fireworks give off heat.
C)Igniting the fireworks requires energy
D)Igniting the fireworks makes an odor.
Answer:B
Explanation:
TOOK DA TEST
As the firework releases heat, it is considered as exothermic reaction. The correct option is B.
What is exothermic reaction?An exothermic reaction is one in which the energy required to break bonds in the reactants is less than the energy released when new bonds form in the products.
Energy is constantly released during an exothermic reaction, often in the form of heat. Exothermic reactions characterize all combustion reactions.
Endothermic reactions are chemical reactions that produce products by absorbing heat energy from their surroundings.
Exothermic reactions are important in forensic science, particularly in the investigation of fires and explosions.
Endothermic refers to a chemical reaction that requires heat and results in cooling of the surroundings.
As fireworks are releasing energy in the form of heat, it can be called as an exothermic reaction.
Thus, the correct option is B.
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Which statement describes an effect of large asteroid and comet impacts?
Answer:
They could cause an organism and population and species to die.
Explanation:
If the asteroid hits on ground, there would be a colossal amount of dust thrown up into the atmosphere and our world. If it hits in water and ocean , then there would be a huge surge in water vapor in the atmosphere. This would result in an increase in rain resulting in landslides and mudslides
what sentence describes all atoms of one element A. They have the same number of isotopes B. They have the same properties C. They have the same number of protons D.They have the same number of neutrons
Answer:
C. They have the same number of protons.
Explanation:
Even though in isotopes, there's uneven number of neutrons, there's always same number of protons.
Hope it helps.
What goes in the rest?
Answer:
E. Mass number
H. Ion
F. Isotopes
I hope you have a great day. I'm sorry that I didn't know C or I.
How many molecules are in each sample?
A. 4.9 g H2O
B. 54.4 g N^2
C. 89 g CCI4
D. 11 g C6H12O6
Answer:
To find the number of molecules first find the number of moles.
number of moles (n) = mass / molar mass (M)
then use the formula
N = n × L
where n = number of moles
N = number of entities
L = Avogadro's constant = 6.02 × 10^23entities to find the number of molecules
A. 4.9 g H2O
m = 4.9g
M = (2*1)+(16×1) = 2 + 16 = 18g/mol
n = 4.9/18 = 0.272mol
N = 0.272 × 6.02 × 10^23
= 1.6374*10^23 molecules of H2O
B. 54.4g of N2
m = 54.4g
M(N2) = 14×2 = 28g/mol
n = 54.4/28 = 1.942mol
N = 1.942 * 6.02*10^23
= 1.1690*10^24 molecules of N2
C. 89 g CCI4
m = 89g
M(CCl4) = 12 + (35.5 × 4) = 154g/mol
n = 89/154 = 0.577mol
N = 0.577 × 6.02 × 10^23
= 3.473*10^23 molecules of CCl4
D. 11 g C6H12O6
m = 11g
M(C6H12O6) = (12×6)+(12×1)+(16×6) =
180g/mol
n = 11/180 = 0.0611mol
N = 0.0611 × 6.02×10^23
= 3.678*10^22 molecules of C6H12O6
Hope this helps
How many grams of carbon dioxide does a hummingbird emit daily?
Answer:
3.5 g CO2
Explanation:
A hummingbird emits up to 3.5 grams of CO2 a day.
Equation:7.9 x 10‒2mol CO2x (44.01 g CO2/ 1 mol CO2)
=3.5 grams
Hope this helps!
In an lonie lattice:
A atoms are bonded to four others in a
Tetrahedral shapes
atoma are packed together in a
regular euble arrangement
e. atoms are bonded with a single
bonds and one double bond
D. atoms are structured in a vast
network of atoms
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Answer:
atoms are bonded with a single bond one double bond