Answer:
oxygen as it has 6 valence electrons
Which of the following elements has the same number of valence electrons as aluminum?
zinc
carbon
silicon
magnesium
or boron
Answer:
boron
Explanation:
Boron and aluminum lie in same group in modern periodic table and both have three valence electrons
How many moles are in 2.70 X 10 24 atoms of copper?
Feel free to comment if u dont understand it :)
According to the concept of Avogadro's number , there are 4.48 moles in 2.70 X 10 ²⁴ atoms of copper.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number
To obtain number of moles divide number of atoms by Avogadro's number that is 2.70 X 10 ²⁴ /6.023×10²³=4.48 moles .
Thus, there are 4.48 moles in 2.70 X 10 ²⁴ atoms of copper.
Learn more about Avogadro's number,here:
https://brainly.com/question/11907018
#SPJ6
a) Find the gas speed of ethane at 200.0 degrees Celsius. ____________
b) What is the rate of effusion of ethane (C2H6) compared to hexane (C6H14) gas at the same temperature? _________________
a. 627.1 m/s
b. the rate of effusion of ethane = 1.7 faster than hexane
Further explanation
Given
T = 200 + 273 = 473 K
Required
a. the gas speed
b. The rate of effusion comparison
Solution
a.
Average velocities of gases can be expressed as root-mean-square averages. (V rms)
[tex]\large {\boxed {\bold {v_ {rms} = \sqrt {\dfrac {3RT} {Mm}}}}[/tex]
R = gas constant, T = temperature, Mm = molar mass of the gas particles
From the question
R = 8,314 J / mol K
T = temperature
Mm = molar mass, kg / mol
Molar mass of Ethane = 30 g/mol = 0.03 kg/mol
[tex]\tt v=\sqrt{\dfrac{3\times 8.314\times 473}{30} }=627.1~m/s[/tex]
b. the effusion rates of two gases = the square root of the inverse of their molar masses:
[tex]\rm \dfrac{r_1}{r_2}=\sqrt{\dfrac{M_2}{M_1} }[/tex]
M₁ = molar mass ethane =30
M₂ = molar mass hexane = 86
[tex]\tt \dfrac{r_1}{r_2}=\sqrt{\dfrac{86}{30} }=1.7[/tex]
the rate of effusion of ethane = 1.7 faster than hexane
Who can help me fill in the blanks?
Answer:
elllo
Explanation:
Match the reaction to the type that best describes it.
Answer:
Answers with detail given below.
Explanation:
1) NaBr + KF → NaF + BrK
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
AB + CD → AD +CB
2) 2Cu + MnCl₂ → 2CuCl + Mn
Single replacement:
It is the reaction in which one elements replace the other element in compound.
AB + C → AC + B
3) CO₂ → O₂ + C
Decomposition reaction:
It is the reaction in which one reactant is break down into two or more product.
AB → A + B
4) C + 2H₂ → CH₄
Combination reaction:
It is the reaction in which two or more simple substance react to give one or more complex product.
Describe what happens to particles of matter as you cool the matter to absolute zero (0 K). In your description, be sure to explain the changes in kinetic energy and particle motion.
Answer:
the particles expand and the kinetic energy i think moves slower
Explanation:
Answer:
Absolute zero is the temperature at which the particles of matter (molecules and atoms) are at their lowest energy points. Some people think that at absolute zero particles lose all energy and stop moving. This is not correct. ... Scientists use lasers to slow atoms when cooling objects to very low temperatures.
1. Freon (CCl2F2) is commonly used in refrigerators and air conditioners as a coolant. How many grams of fluorine are there in the 2.00 lbs of Freon necessary for an air conditioner? (1 lb = 454 g)
Answer:
285g of fluorine
Explanation:
To solve this problem we need to find the mass of Freon in grams. Then, with its molar mass we can find moles of freon and, as 1 mole of Freon, CCl₂F₂, contains 2 moles of fluorine, we can find moles of fluorine and its mass:
Mass Freon:
2.00lbs * (454g / 1lb) = 908g of Freon
Moles freon -Molar mass: 120.91g/mol- and moles of fluorine:
908g of Freon * (1mol / 120.91g) =
7.5 moles of freon * (2moles Fluorine / mole Freon): 15 moles of fluorine
Mass fluorine -Atomic mass: 19g/mol-:
15 moles F * (19g / mol) =
285g of fluorineMg (50.0 g) and HCI (75.0 g) were added together to produce MgCl2 and H2
Mg + 2HCl → MgCl2 + H2
a) What mass of hydrogen gas produced in this reaction?
b) how much of the excess reactant is left over?
Answer:
Mass of hydrogen produced = 2.1 g
Mass of excess reactant left = 25.2 g
Explanation:
Given data:
Mass of Mg = 50.0 g
Mass of HCl = 75.0 g
Mass of hydrogen produced = ?
Mass of excess reactant left = ?
Solution:
Chemical equation:
Mg + 2HCl → MgCl₂ + H₂
Number of moles of Mg:
Number of moles = mass/molar mass
Number of moles = 50 g/ 24 g/mol
Number of moles = 2.1 mol
Number of moles of HCl:
Number of moles = mass/molar mass
Number of moles = 75 g/ 36.5 g/mol
Number of moles = 2.1 mol
now we will compare the moles of hydrogen gas with both reactant.
Mg : H₂
1 : 1
2.1 : 2.1
HCl : H₂
2 : 1
2.1 : 1/2×2.1 = 1.05 mol
HCl is limiting reactant and will limit the yield of hydrogen gas.
Mass of hydrogen:
Mass = number of moles × molar mass
Mass= 1.05 mol ×2 g/mol
Mass = 2.1 g
Mg is present in excess.
Mass of Mg left:
HCl : Mg
2 : 1
2.1 : 1/2×2.1 = 1.05
Out of 2.1 moles of Mg 1.05 react with HCl.
Moles of Mg left = 2.1 mol - 1.05 mol = 1.05 mol
Mass of Mg left:
Mass = number of moles × molar mass
Mass = 1.05 mol × 24 g/mol
Mass = 25.2 g
Help please!!
The half life of lutetium-117 is 6.75 days.
Calculate the percentage remaining after 27 days.
Answer:
6.25%
Explanation:
Given data:
Half life of lutetium-117 = 6.75 days
Percentage remaining after 27 days = ?
Solution;
Number of half lives = Time elapsed / half life
Number of half lives = 27 days / 6.75 days
Number of half lives = 4
At time zero = 100%
At first half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
At 3rd half life = 25%/2 = 12.5%
At 4th half life = 12.5%/2 = 6.25%
equation invalid?
Al +202
→ A1203
O A. An atom of aluminum (Al) is created in the reaction.
B. An atom of oxygen (O) is destroyed in the reaction.
O C. The equation violates the Law of Conservation of Mass.
O D. All of the above.
1 View Gizmo
Answer:
B. an atom of oxygen o is destroyed in the reaction
Respond to the following prompt
Knowing what you know about photosynthesis, explain how the process may help reduce global warming.
Define the ground state of an atom
Explanation:
The nucleus of an atom is surround by electrons that occupy shells, or orbitals of varying energy levels. The ground state of an electron, the energy level it normally occupies, is the state of lowest energy for that electron. There is also a maximum energy that each electron can have and still be part of its atom.
Arrange the following atoms in order of decreasing atomic radius: Ga,As,Sn,Sb,Te
Answer:
Sn, Sb, Te, Ga, As
Explanation:
How many grams do 3.6 × 10^20 atoms of sodium weigh?
Answer in units of g.
Second time posting as someone else answered incorrectly.
Answer:
13.749 x 10 -3 g
Explanation:
take the number of atoms that you have divided by Avogadro's number and then multiply by the molar mass of the element. :)
How many moles of carbon are in 5.25 g sucrose? How many moles of hydrogen? How many moles of oxygen?
Answer:
63 moles of carbon atoms, 115.5 moles of hydrogen atoms, and 57.75 moles of oxygen atoms i believe :)
Metal X has a specific heat capacity of 0.982 Jg∙°C . If 525.0 g of Metal X increases in temperature from 32.00° C to 43.00° C, how much energy will be absorbed?
Answer:
Q = 5671.05 J
Explanation:
Given data:
Mass of metal = 525 g
Initial temperature = 32.0 °C
Fina temperature = 43.0 °C
Heat absorbed by metal = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
specific heat capacity of metal X = 0.982 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 43.00°C - 32.00°C
ΔT = 11.00°C
Q = 525 g × 0.982 J/g.°C × 11.00°C
Q = 5671.05 J
Calculate the mass of hydrogen in 57.010 grams of ammonium hydrogen phosphate. Use dimensional analysis.
Answer:
4.59 grams of hydrogen
Explanation:
57.010 g of ammonium phosphate * 1 mol / 149 g of ammonium phosphate * 12.0 g H * / 1 mol = 4.591409396.
But with sig figs, it rounds to 4.59.
So the final answer is 4.59 grams of hydrogen.
4.59g is the mass of hydrogen in 57.010 grams of ammonium hydrogen phosphate. A mole is just a measuring scale.
What is mole?A mole is just a measuring scale. In reality, it is one of the International System for Units' seven foundation units (SI). When already-existing units are insufficient, new ones are created. Using absolute amounts of atoms, molecules, or ions would be problematic as well since chemical reactions frequently occur at levels that use grams would be inappropriate.
A mole consists of precisely 6.022140761023 particles. The "particles" might be anything, from tiny things like electrons and atoms to enormous things like stars or elephants.
57.010 g of ammonium hydrogen phosphate× 1 mol / 149 g of ammonium phosphate ×12.0 g H× / 1 mol = 4.59g of hydrogen
Therefore, 4.59g is the mass of hydrogen in 57.010 grams of ammonium hydrogen phosphate.
To know more about mole, here:
https://brainly.com/question/15209553
#SPJ2
Aqueous solutions of potassium chloride and silver nitrate are mixed.
Write the balanced net ionic equation
Answer:
Sorry how no this equation guys
Which statement is true of gamma radiation?
A. Gamma radiation can pass through your body
B. Gamma radiation is always dangerous to the body.
C. Gamma radiation is produced when a neutron turns into a preton
D. Gamma radiation cannot go through surfaces rather, it will beures
off them.
Answer: A. Gamma radiation can pass through your body
Explanation:
Let's use the Process of Elimination for this problem.
We will start off with B. Gamma radiation is always dangerous to the body.
Facts: Gamma radiation are not always dangerous to the body. Most of the time, Gamma rays and radiation will go through with little to no effect at all. So, now we know that the answer can not be B. Gamma radiation is always dangerous to the body.
Next, let's check if C. Gamma radiation is produced when a neutron turns into a proton is true.
Facts: Gamma radiation has nothing to do with neutrons turning into protons and protons turning into neutrons. Gamma rays are a type of radiation that is everywhere. Gamma rays do not make neutrons into protons. Now, we will eliminate option C. Gamma radiation is produced when a neutron turns into a proton.
Let's check if D. Gamma radiation cannot go through surfaces rather, it will beures off them is true or not is true or not.
Facts: Gamma rays can enter your body, they do not just bounce off of your body. Gamma rays are invisible and have no weight. They are like lasers and they can enter your body. Now, we know the answer should not be D. Gamma radiation cannot go through surfaces rather, it will beures off them is not a true statement.
Finally, let's check if A. Gamma radiation can pass through your body is true or not.
Facts: Gamma rays can pass through your body because it is like a natural laser. They can also cause ionizations that can damage tissue in your body. But most of the time, the damage to your tissue is minor. So, we know A. Gamma radiation can pass through your body is a true statement.
Therefore, we got our answer. A. Gamma radiation can pass through your body is the correct option.
question shown in picture tysm!!!
Answer:
the answer is the second one.
if you push a crate with 50N of force for 10 meters in 5 seconds how much power dis u use
Answer:
Hi... Your answer is 10*50=500
Answer:
50x10 = 500 ; 500/5 = 100 watts
Explanation:
W/t /Force x Distance
the power is equal to the work done to the object divided by time.
help! why are chemical equations always balanced?
Answer:
C
Explanation:
The Law of Conservation of Mass states that matter cannot be created or destroyed and must be conserved. I is stating matter cannot be created, which is true. II is saying that matter can only be rearranged/conserved, which again is true. III states matter cannot be destroyed, which is also true. IV is incorrect because it doesn't make sense. Matter does matter.
ASAP HELPPP PLZZ I WILL GIVE BRAINLIEST
Ocean currents contribute to global climates and occur due to differences in temperature, salinity, and density. WHY do you THINK these differences can cause currents to form?
plzzzz
Answer:
The rise and fall of the tides. Tides create a current in the oceans, which are strongest near the shore, and in bays and estuaries along the coast.
Winds drive currents that are at or near the ocean's surface.
Thermohaline circulation. This is a process driven by density differences in water due to temperature (thermo) and salinity variations in different parts of the ocean. Currents driven by thermohaline circulation occur at both deep and shallow ocean levels and move much slower than tidal or surface currents.
Currents affect the Earth's climate by driving warm water from the Equator and cold water from the poles around the Earth.
Explanation:
hope this helps
What is the number of electronsin hydrogen?
Answer:
1
Explanation:
Sound travels most quickly through solids because _____.
solids have greater frequencies
solids have more energy than other states of matter
solids have more decibels
the molecules in solids are very close together
Answer:
The answer is: Because solids are the most sense.
Option (b) is the correct answer.
Explanation:
The distance between molecules in solids r very small.Because they are so close, they can collide very quickly, i.e. it takes less time for a molecule of the solid to 'bump' into its neighbor. Solids are packed together tighter than liquids and gases, hence sound travels fastest in solids.It is true that sound travels faster in solids. This is because in solid substances, molecules are much closer to each other due to which transfer of energy is much faster.
On the other hand, molecules in a liquid and gas are farther apart from each other due to which there will be less transfer of energy. As a result, sound does not travel quickly through liquids and gases.
Thus, we can conclude that sound travels most quickly through solids because the molecules in solids are very close together.
Answer:
yea, what they said.
Explanation:
Can somebody help me. Will mark brainliest.
Answer:
2.27%
Explanation:
The observed value of the boiling point = 71.8°C
The actual value of the boiling point = 70.2°C
We need to find the percentage error of the student's measurement. The percentage error in any value is given by :
[tex]\%=\dfrac{\text{calculated value-actual value}}{\text{actual value}}\times 100\\\\=\dfrac{71.8-70.2}{70.2}\times 100\\\\=2.27\%[/tex]
So, the required percentage error is 2.27%.
which expression has a value of 10
A. (10+10)/5-3
B. (10+10)/(5-3)
C. (10+10/5)-3
D. 10+10/(5-3)
(math)
which statement describes the movement of carbon dioxide in the carbon cycle?
A. The gas leaves the biosphere as animals breathe in air.
B. The gas leaves the atmosphere as plants use it to make sugar.
C. The gas enters the cryosphere as ice sheets melt.
D. The gas enters the hydrosphere as sugar dissolves in water.
Answer:
C. The gas enters the cryosphere as ice sheets
Answer:
D
Explanation:
Which type of molecule is shown below?
A. Alcohol
B. Ester
C. Amine
D. Ketone
Answer:
Ketone molecule
Explanation:
The type of molecule shown above is ketone molecule.
What is molecule?A molecule is a group of two or more atoms that are chemically combine together or are tightly held together by attractive forces.
What is ketone?A ketone is an organic compound in which the carbonyl group is attached to a carbon atom within the carbon chain. The general formula for a ketone is RC(=O)R' where R and R' are alkyl or aryl groups.Hence, we can conclude that option D is the answer.
To learn more about ketone and molecule here
https://brainly.com/question/20503473
#SPJ2
How are you able to see cells?
With contemporary light microscopes.
Answer:
Contemporary light microscopes are able to magnify objects up to about a thousand times. Since most cells are between 1 and 100 μm in diameter, they can be observed by light microscopy, as can some of the larger subcellular organelles, such as nuclei, chloroplasts, and mitochondria.