Answer:
D) 10.812
Explanation:
Given:
The two isotopes of boron (B).
Boron-10 has an abundance of 19.8% and Boron -11 has an abundance of 80.2%
To find:
The atomic mass of europium.
Solution:
Mass of Boron-10 = 10.013 amu
The percentage abundance of Boron-10 = 19.8%
The fractional abundance of Boron-10 =0.198
Mass of Boron-11 = 11.009 amu
The percentage abundance of Boron-11= 80.2%
The fractional abundance of Boron-11= 0.802
The average atomic mass of Boron = A.M
A.M = Mass of isotope x Fractional abundance of isotope
= 10.013amu x 0.198 +11.009amu x 0.802 = 10.81u
Therefore, D) 10.812 amu is the atomic mass of boron.
1. Every summer Cheyanne drives to California. It is 3600 km to get there. If she spends 32 hours driving, what is her speed?
Answer:
Their speed = 69.9043 miles per hour
orTheir speed = 112.5 kilometers per hour
Explanation:
answer pls asap!!!!!!
Answer:
im going to go with letter c
Explanation:
Answer:
Changes can occur to physical properties of a substance, but the chemical composition of the substance remains the same.
Explanation:
Physical change is a change in which there is no change in the chemical arrangement and thus there is no redistribution of atoms. No new substances are formed. There is only change in size, shape and phase etc.
[tex]H_2O(l)[/tex]→[tex]H_2O(g)[/tex]
Chemical change is a change in which there is change in the chemical arrangement and thus there is redistribution of atoms. which leads to formation of new substances.
[tex]2Na+Cl_2[/tex]→[tex]2NaCl[/tex]
HELP PLEASE I HAVE A TEST TODAY AND I DON'T UNDERSTAND ANY OF THIS...
265 kilojoules of energy are added to 150g of ice at 0 degrees C how many grams of water would boil away
Answer:
About 67 grams or 67.39 grams
Explanation:
First you would have to remember a few things:
enthalpy to melt ice is called enthalpy of fusion. this value is 6.02kJ/mol
of ice
it takes 4.18 joules to raise 1 gram of liquid water 1 degree C
water boils at 100 degrees C and water melts above 0 degrees C
1 kilojoules is 1000 joules
water's enthalpy of vaporization (steam) is 40.68 kJ/mol
a mole of water is 18.02 grams
we also have to assume the ice is at 0 degrees C
Step 1
Now start with your ice. The enthalpy of fusion for ice is calculated with this formula:
q = n x ΔH q= energy, n = moles of water, ΔH=enthalpy of fusion
Calculate how many moles of ice you have:
150g x (1 mol / 18.02 g) = 8.32 moles
Put that into the equation:
q = 8.32 mol x 6.02 = 50.09 kJ of energy to melt 150g of ice
Step 2
To raise 1 gram of water to the boiling point, it would take 4.18 joules times 100 (degrees C) or 418 joules.
So if it takes 418 joules for just 1 gram of water, it would take 150 times that amount to raise 150g to 100 degrees C. 418 x 150 = 62,700 joules or 62.7 kilojoules.
So far you have already used 50.09 kJ to melt the ice and another 62.7 kJ to bring the water to boiling. That's a total of 112.79 kJ.
Step 3
The final step is to see how much energy is left to vaporize the water.
Subtract the energy you used so far from what you were told you have.
265 kJ - 112.79 kJ = 152.21 kJ
Again q = mol x ΔH (vaporization)
You know you only have 152.21 kJ left so find out how many moles that will vaporize.
152.21 kJ = mol x 40.68 or mol = 152.21 / 40.68 = 3.74 moles
This tells you that you have vaporized 3.74 moles with the energy you have left.
Convert that back to grams.
3.74 mol x ( 18.02 g / 1 mol ) = 67.39 grams
Which statement best explains the difference between polar and nonpolar covalent bonds?(1 point)
Polar covalent bonds give/take electrons, while nonpolar covalent bonds share electrons.
Polar covalent bonds share electrons equally, while nonpolar covalent bonds share electrons unequally.
Polar covalent bonds share electrons unequally, while nonpolar covalent bonds share electrons equally.
Polar covalent bonds share electrons, while nonpolar covalent bonds give/take electrons.
Covalent bonding can be defined as the sharing of electrons between two atoms.
The statement which best explains the difference between polar and nonpolar covalent bonds is "Polar covalent bonds share electrons unequally, while nonpolar covalent bonds share electrons equally"
We have:
Polar covalent bond is a chemical bond in which electrons are shared unequally or unevenly between two atoms. Non-polar covalent bond is a chemical bond in which electrons are shared evenly or equally between two atoms.Therefore, the statement which best explains the difference between polar and nonpolar covalent bonds is "Polar covalent bonds share electrons unequally, while nonpolar covalent bonds share electrons equally"
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Someone pls help me I will make you brain
Answer:
the second answer
Explanation:
Answer:
A Erosion of structures and buildings
Explanation:
Aluminum is manufactured using electrolysis. Carbon electrodes are used. Describe the nature of the electrolyte.
At which electrode is the aluminum produced?
Answer:
The traditional electrolyte for aluminium electrolysis is based on molten cryolite (Na3AlF6), acting as solvent for the raw material, alumina (Al2O3).Metals are found in ores combined with other elements. Electrolysis can be used to extract a more reactive metal from the ore.
Aluminum can and is used as both anodes and cathodes in electrochemical cells, but there are some peculiarities to using it as an anode in aqueous solutions. As you note, aluminum forms a passivating oxide layer quite readily, even by exposure to atmosphere. In an aqueous solution, if the potential is high enough, OH− and O2− are generated at the anode, which can then react with the aluminum to produce aluminum oxide. Al^3+ can also be generated directly. The electric field will draw the anions through the growing aluminum oxide layer towards the aluminum surface and the Al^3+ towards the solution, making the oxide layer grow both away from the electrode surface and into the surface of the electrode. In this way, coatings thicker than the normal passivation in air can be produced. However, aluminum oxide is a good electrical insulator, thus if a dense non-porous layer is grown, it will become impossible to pass current through it and growth will stop, leaving a relatively thin oxide layer (this is how the dielectric layers in electrolytic capacitors are made). This is the normal behaviour in aqueous solutions at near-neutral pH (5–7).
However, if a thick aluminum oxide layer is desired (e.g. to produce coatings on aluminum parts for dying or durability), maintaining porosity is necessary to avoid completely blocking access to the surface. One technique that is commonly used is using a low pH solution, which tends to redissolve some of the oxide and neutralize some of the formed OH−, leaving pores in the oxide layer through which the ions can travel and continue to react. These pores also give a good structure to retain dyes or lubricants, but generally need to be sealed after to protect against corrosion.
Which layer or layers of Earth provide the heat and energy that fuels convection?
The layer of Earth which provide transfer from the white core to the lithosphere that fuels convection is the mantle.
What is the Mantle layer?A mantle can be described as a layer inside a planetary body bounded above a crust and below a core. Mantles are composed of rock or ice and are usually the largest massive layer of the planetary body.
The mantle layer of the earth is a layer of silicate rock between the crust and the outer core. The mass of the mantle of 4.01 × 10²⁴ kg which is 67% of the mass of the Earth. It's a thickness of 2,900 kilometers making up about 84% of Earth's volume.
The mantle layer is predominantly solid, but it behaves as a viscous fluid. At mid-ocean ridges, partial melting of the mantle produces oceanic crust, and at subduction zones, partial melting of the mantle produces continental crust.
The temperatures range of the mantle from 200 °C at the upper boundary with the crust to 4,000 °C at the core-mantle boundary. The convection of the mantle is a chaotic process, the mantle transfers heat that fuels convection.
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What is a paper clip, a colloid? solution? or a suspension?
Answer:
I'm gonna guess it's a suspension
Explanation:
let me know if I'm wrong
bp’s efforts to close the blowout preventer and install a containment dome following an explosion on the deepwater horizon drilling rig is an example of ________ change.
The British Petroleum (bp's) effort to close the blowout preventer and install a containment dome following an explosion on the deepwater horizon drilling rig is an example of regulatory policy change.
The deepwater horizon drilling rig is a semi-submersible, transportable, floating, flexibly oriented drilling rig that could work in sea depths of up to 10,000 feet which is approximately 3,000 meters.
During the explosion that occurred in April 2010, British Petroleum made several efforts to contain the damages made and to prevent further outbreaks of disasters.
Part of the changes was shifting from a blowout preventer that has a specialized valve to seal, manage, and monitor oil and gas wells in order to prevent blowouts to a containment dome (a crucial component of a system meant to control an oil well's underwater blowout).
Therefore, we can conclude that the British Petroleum (bp's) effort to close the blowout preventer and install a containment dome following an explosion on the deepwater horizon drilling rig is an example of regulatory policy change.
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Your future is affected by your choices today? I agree or disagree
Answer:
The choice that we had decided on doing today factors our future because whatever choice we decide on doing in the present day can impact how our life will play out in the future. ... After all, it is your life, so whatever you chose to do, you have the power to decide and create what you think would be best for you
Explanation:
Cho 200 g dung dịch NaCl 0,5M tác dụng hết với 400 ml AgNO3. Sau phản ứng thu được kết tủa và dung dịch không màu
a, Viết phương trình hóa học xảy ra?
b, Tính khối lương kết tủa tạo thành
c, Tính nồng độ mol của dung dịch AgNO3 đã tham gia phản ứng.
Answer:
Explanation:
a. NaCl+ AgNO3-----> NaNO3+ AgCl
b. Số mol của NaCl= 0,2*0,5= 0,1 (mol)
------> Số mol của kết tủa AgCl tạo thành= 0,1 mol (dựa vào phương trình hóa học)
-----> Khối lượng của kết tủa AgCl tạo thành= 0,1*143,5=14,35(g)
c. Số mol của AgNO3= số mol của NaCl= 0,1 (mol)
------> Nồng độ mol của dd AgNO3 đã tham gia phản ứng= [tex]\frac{0,1}{0,4}[/tex]=0,25(M)
Each of these Ionic Compounds are named INCORRECTLY. 1. Find and describe the mistake 2. Correctly name the compound. CaCl2 - Calcium Chlorine CuS - Copper Sulfide Li3P - Trilithium Phosphide CuBr - Copper(II) Bromide NaOH - Sodium Hydrogen Oxide
Explanation:
The nomenclature of ionic compounds is given by:
1. Positive is written first. And if the metal atom has various oxidation states then its oxidation state is to be mentioned in brackets with help of roman numbers
2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.
1.) : Calcium chloride (Correct)
In the given compound, calcium has oxidation state of +2 and chlorine has oxidation state of -1.The name is correct.
2.) : Copper (II) oxide (Incorrect)
In the given compound,copper has the oxidation state of +1 and oxygen has oxidation state of -2.So ,the correct name will be Copper (I) oxide.
3.) : Lead (II) sulfide (Incorrect)
In the given compound, lead has the oxidation state of +4 and sulfur has oxidation state of -2. So ,the correct name will be Lead (IV) sulfide.
Write down the names, physical properties, and inertness of NOBLE GASES ( group no. 8)
Note:
*Please don't copy from anywhere
*50 POINTS!!!!!!!!
Answer:
There's No Answer Im Sorry
Each mineral group has a distinctive chemical feature such as
a. oxides are a metal combined with oxygen
b. sulfides are a metal combined with sulfur and oxygen
c. halides are a salt combined with a metallic atom
d. phosphates are made of phosphate polygons
Answer:
A
Explanation:
how many atoms of neon are present in 1.30 moles of neon?
Answer:
7.83 x 10^23 atoms
Explanation:
Which of these statements is not true?
A. Atoms of the same element can have different masses
B. The nucleus of an atom has a positive charge
C. Atoms of isotopes of an element have different numbers of protons
D. Atoms are mostly empty space
Option 5
Answer:
c.
Explanation:
They can have different neutron numbers, not proton numbers. If they were to have different proton numbers it would be classified as a different element.
Number 8 question need help
Answer:
where is the question
Explanation:
pls. send it
Three fundamental laws of chemical combination
Answer:
the law of multiple proportions, law of definite proportions, and law of conservation of mass.
Explanation:
(Hope this helps can I pls have brainlist (crown)☺️)
a molecule that carries information across a synaptic cleft is a
1. Cooking pots are provided with wooden or plastic handles .Why?
Answer:
So the heat doesn't transfer to the handle and heat it up causing you to burn yourself in cooking process
Explanation:
Hope this helps! Happy Halloween
Cooking pots are provided with wooden or plastic handles because wood or plastic handles are bad conductors of heat. Hence, the heat from the hot appliances does not flow to our hands with the result that we can handle them without any difficulty.
cuales son los nombres de la distribución de los electrones en un átomo ?
what process in the natural world converts radiant energy into chemical energy?
Answer:
Photosynthesis
Explanation:
Photosynthesis is the process in which plants collect radiant energy (from the Sun) and transform it into chemical energy.
Answer:
Photosynthesis is the process in which plants collect radiant energy (from the Sun) and transform it into chemical energy.
Explanation:
BECAUSE I SAID, btw its right i promise
Question 4 (2 points)
(02.04 MC)
Jackson is making dinner and is trying to dissolve salt into a pot of water. The salt is dissolving slowly. What should Jackson do to speed up the
rate of dissolving? (2 points)
O.
Ob
Oc
He should put larger salt particles in the water.
He should hear the water to a higher temperature.
He should completely stop stirring the pot of water.
He should slow down the speed he is stirring the pot
Od
Question 5 (2 points)
(02.04 MC
ribed below
Answer:
B. He should heat the water to a higher temperature.
Explanation:
Tiny particles that make up water and salt vibrate at higher speeds in hotter temperatures, which mixes the salt and water faster. This causes salt to dissolve much faster.
Ryan and Abigail are conducting an experiment. They place six ice cubes into a beaker and find the combined mass. They allow the ice cubes to melt and find the combined mass of the beaker and the liquid water.
A
A
Before
After
What can the students expect to be true about the two masses?
The mass of the ice cubes will be greater because solids are more dense.
The mass of the ice cubes will be greater because they took up more space in the beaker.
The mass of the ice cubes and the water will be equal because the same amount of matter is in the beaker
The mass of the ice cubes and the water will be equal because their particles have the same amount of energy
B
c
С
D
The mass of the ice cubes and the water will be equal because the same amount of matter is in the beaker.
Matter is anything that has mass and occupy space. All substances are composed of matter. According to the law of conservation of mass, matter can neither be created nor destroyed but can be converted from one form to another.
Since mass is the quantity of matter in a substance, the mass of the ice cubes and the water will be equal because the same amount of matter is in the beaker.
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answer pls ASAP will mark the brainliest
For me that is the first :
Both the identity and the properties of a substance change.
1. What atoms make up a molecule of Water?
2. What atoms make up a molecule of Carbon Dioxide?
I would appreciate it if this got answered and I will mark as brainliest, thank you.
Explanation:
Atoms join together to form molecules. A water molecule has three atoms: two hydrogen (H) atoms and one oxygen (O) atom
Carbon dioxide is a colorless and non-flammable gas at normal temperature and pressure. Although much less abundant than nitrogen and oxygen in Earth's atmosphere, carbon dioxide is an important constituent of our planet's air. A molecule of carbon dioxide (CO2) is made up of one carbon atom and two oxygen atoms.
I hope you got it..... ♥️
Answer:
1) 1Atoms join together to form molecules. A water molecule has three atoms: two hydrogen (H) atoms and one oxygen (O) atom. **
2) Although much less abundant than nitrogen and oxygen in Earth's atmosphere, carbon dioxide is an important constituent of our planet's air. A molecule of carbon dioxide (CO2) is made up of one carbon atom and two oxygen atoms. Carbon dioxide is an important greenhouse gas that helps to trap heat in our atmosphere. ^^
yall help, i missed like a week
some of them are wrong, I need all of 1 and 2
Answer:
a. Azane
b. sulphur hexachloride
c.carbon tetrachloride
d. Carbon disulfide
e.Umbelliferone
f.Disilicon hexabromide
g. Dinitrogen trifluoride
h.
If you weigh 60 pounds on Earth, your weight is _______on the moon (the moon has 1/6 the gravity of Earth).
Answer:
10 pounds
Explanation:
If the moon has 1/6 the gravity of earth, divide your weight on earth by 6 to find your weight on the moon
60 / 6 = 10 pounds
Electrons are transferred from one atom to another.
Options:
Ionic Bond or Covalent Bond?
Answer:
ionic
Explanation:
ionic transfer of e^- ions formed (charges)
ionic=non-metal+ metal
ex: F+Ca
covalent sharing e^- no true charges
covalent= non-metal+ non-metal
ex: F+P
( my notes)
.
You should be able to
these groups on the periodic table, and know their
properties.
Answer:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties.
Explanation:
I HOPE NAKATULONG PO AKO:)PA BRAINLEST NLNG PO SANA:(