Answers
Answer: với những bài không biết bảo toàn e thì bạn có thể dùng bảo toàn nguyên tố cũng được, với pt hữu cơ thì ưu tiên cân bằng C, H trước rồi tới O
Explanation:
Related Questions
If repeated measurements agree closely but differ widely from accepted value these measurements are?
Answers
d. precise, but not accurate
Which ion has a smaller size,1)N---,O--,F-and Ne 2) Cl-,Br- and I ?Why
Help me to solve it!
Answers
Answer:
nitrogen because it has less number of protons and electrons, thus a samller atomic mass
Explanation:
Explanation:
Ne have smaller size because Ne have no negative charge compare to N, O and F which negative charge depends on size of an atom, Therefore more the negative charge , more will be the size of atom.Cl- have smaller size because as we go down the group, Size of the atom increase as Cl<Br<I irrespective to the atomic charge. What is the total number of protons, neutrons,
and electrons in a cadmium, Cd, atom that has
a mass number of 112?
PLEASE I NEED HELP
Answers
Answer:
# of Proton: 48
# of Electron: 48
# ofNeutron: 64
Explanation:
The atomic number of cadmium is 48.
∴ atomic number = protons = electrons = 48.
Neutrons = mass number - atomic number
∴ Neutrons = 112 - 48 = 64.
⇒ number of protons= 48; neutrons= 64; electrons=48
3. How many seconds would it
take o radio wave to travel
from the planet Mars to
Earth when they are the
closest?
(Closest distance from Mars
to Earth = 54.6 million
kilometers)
Answers
Answer:
270 sec . ( = 4 min . 30 sec . ) Explanation: Any radio wave is moving at the speed of light, regardless of the frequency, so the frequency should be superfluous information. The speed is light is close to 300 , 000 k m s I take the distance you are given, to be 8.2 ⋅ 10 7 k m (since 8.2 ⋅ 107 k m doesn't make good sense - it's less than 1000 km) i.e. 82 , 000 , 000 km.
Before we actually compute this, we can notice that this is a little more than half the distance of the earth from the sun (150 mill. km), a distance the light uses 500 sek. = 8 min 20 sec. to travel, so we should get about 4 1 2 min for the radio wave to reach Mars from the earth.
Actual calculation: 82 , 000 , 000 km/300 , 000 k m s = 820 3 s = 273.3 s As the distance is given with 2 significant figures, we round this off to 270 sec = 4 min 30 sec.
Explantation:
Hope this helps =)
8. Explain why fluorine has a smaller atomic radius than chlorine.
Answers
Answer:
Explanation: Fluorine has a smaller atomic radius than oxygen because fluorine has a larger nuclear charge. Fluorine has a smaller radius than chlorine because it has eight fewer electrons.
There are various kind of elements that are present in periodic table. Some elements are harmful, some are noble gases. The size difference between chlorine and fluorine can be explained on the basis of number of shells.
What is periodic table?Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
As we go down along the periodic table the number of shells increases.
Atomic number of F= 9
Electronic configuration of F=2, 7
Atomic number of Cl= 17
Electronic configuration of chlorine = 2,8,7
So, there are total 2 shells in Fluorine while chlorine has 3 shells. The distance of shells increases with increase in number of shells. This makes the size of chlorine more bigger than fluorine.
Therefore, the size difference between chlorine and fluorine can be explained on the basis of number of shells.
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In a varve, summer is represented by _____.
sediment from melting glaciers being deposited in lakes
clay from wind-blown dust
ash from nearby volcanoes
None of these
Answers
Answer:
answer b
Explanation:
i took the test
Answer:
Hey let's talk here if you want
iii. According to the law of conservation of energy, what can change? (1 point) FAKES WILL BE REPORTED I EILL GIVE U BRAINLIEST
Answers
Answer:
Nothing can change because energy can't be made or destroyed
Explanation:
The trend towards smaller atomic radii as one moves to the right in a period is _____. A) faulty, as atomic radii in a period are nearly uniform in size. B) because of electron pair repulsion causing the expansion of the orbitals. C) wrong. Atomic radii increase across a period left to right as the larger d and p orbitals are occupied after the s orbital. D) due to the effective nuclear charge decreasing. E) due to the effective nuclear charge increasing.
Answers
Answer:
It’s E. Nuclear charge increasing
Explanation: it just is
There are various kind of elements that are present in periodic table. Some elements are harmful, some are radioactive, some are noble gases. Option E is correct option.
What is periodic table?Periodic table is a table in which we find elements with properties like metals, non metals, metalloids and radioactive element arranges in increasing atomic number.
As we go from left to right in periodic table the atomic radii decreases because of increase in effective nuclear charge . There is no increase in number of shells only the number of electrons increases which increase the number of protons in the nucleus and hence the effective nuclear charge of the atom which makes the size of atom contract.
Therefore, the trend towards smaller atomic radii as one moves to the right in a period is due to the effective nuclear charge increasing. The correct option is option E.
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A flagpole is an example of what type of pulley system?
A. Movable pulley
B. Fixed pulley
C. Block and tackle?
Answers
Answer:
B
Explanation:
i learned the pulley system in school
Answer:
B. Fixed pulley
Explanation:
Name and Title:
Include your name, instructor's name, date, and name of lab.
Objectives(s):
In your own words, what is the purpose of this lab?
Hypothesis:
In this section, please include the if/then statements you developed during your lab activity. These statements reflect your predicted outcomes for the experiment.
Procedure:
The materials and procedures are listed in your virtual lab. You do not need to repeat them here. However, you should note if you experienced any errors or other factors that might affect your outcome. Using your summary questions at the end of your virtual lab activity, please clearly define the dependent and independent variables of the experiment.
Data:
Record the composition of each of your compounds below. Be sure to include the number of atoms for each element. An example has been supplied for you.
Compound Name Chemical Formula Sodium (Na) Atoms Calcium (Ca) Atoms Hydrogen (H) Atoms Oxygen (O) Atoms Carbon (C) Atoms Chlorine (Cl) Atoms
Ex: Sodium
hypochlorite NaClO 1 0 0 1 0 1
Conclusion:
Your conclusion will include a summary of the lab results and an interpretation of the results. Please answer all questions in complete sentences using your own words.
Using two to three sentences, summarize what you investigated and observed in this lab.
Why do you believe knowing how elements and compounds react together is essential in everyday matters?
Some elements are more "reactive" than other elements; why do you think this is?
Choose one of the compounds from the table and explain how you know the numbers of atoms in your formula.
Is it possible for two different compounds to be made from the exact same two elements? Why or why not? With a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?
Answers
Answer:
I dont know your intructors name also do this yourself we dont know what the lab is
Explanation:
How many mg of salt are in a 2.78 kg bag of salt?
Answers
Answer:
2,780,000mg
Explanation:
Using the Metric Staircase photo provided, you can calculate how many mg there are in 2.78 kg by simply moving the decimal point six places to the right, since the "Kilo" step takes six places to move to the "Milli" step.
2.78 kg
---------------
2 7 8 0 0 0 0 .
we can see that the decimal point is moved to the right six places.
Answer:
2,780,000mg
if the reactants of a reaction have an initial mass of 25g what should the mass of the products be
Answers
Answer:
It remains the same
Explanation:
The law of conservation of mass states that, during a chemical reaction, the total mass of the products must be equal to the total mass of the reactants.
Can you use molecular orbital theory to explain why fluorine is such a highly reactive gas?
Answers
Single bonds are easier to break and therefore more reactive. So the answer is yes.
The reactivity of fluorine can be explained from molecular orbital theory with the calculation of the bond order.
What is molecular orbital theory?The molecular orbital theory is assigned to explain the movement of the electrons in the bonding and anti-bonding orbitals.
The number of atom in the bonding and anti-bonding atomic orbits results in the elucidation of the bond order for the element.
The bond order and reactivity are inversely proportional to each other. The higher bond order depicts the presence of stronger bonds between the molecules and lower reactivity.
The bond order of fluorine atom is elucidated from the molecular orbital theory. The bond order of fluorine atom is 1, that explains the high reactivity of fluorine.
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What is the resultant force of a motorcycle travelling at 500 N with an air resistance of 50 N
Answers
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
The resultant force is equal to :
[tex]500 - 50[/tex][tex]450 \: \: N[/tex]
After many years,which cross section would pay likely result
Answers
What mass of glucose would you need (in g) to have 0.8 mol, given that the molar mass of glucose is 180 g mol-1?
Answers
Explanation:
Mass of glucose = moles × molar mass
∴ Mass of glucose = 0.8 mol × 180 g mol⁻¹
= 144 g
∴ the mass of glucose you need to have 0.8 mol of glucose = 144 g
A dry soil sample has a volume of 500 mL. After 400 mL of water are added to the soil, the soil becomes saturated with 150 mL of surface water left on top. What is the porosity of the soil?
Please help me
Answers
BaCO3(s) → BaO(s) + CO2(g)
(a) A student heated a 10.0 g sample of barium carbonate until it was fully decomposed.
(i) Calculate the number of moles of barium carbonate the student used.
moles of barium carbonate =
Answers
number of moles = mass
molar mass
BaCO3 molar mass = 197.34 g/mol
mass = 10g
n = 10/197.34
n = 0.05moles.
The number of moles of barium carbonate used are 0.05moles.
Which of the following is the source of energy for nuclear energy?
Select one:
O a. Nuclear fusion
O b. Nuclear fission
OC. Nuclear Inclusions
O d. Nuclear Reactions
Answers
Answer:
b. Nuclear fission
Explanation:
HELPPP PLZZZ ASAPPPPPO
Answers
Answer:
0.000471698
Explanation:
divide 0.125 by 265.
Can someone help please?
Copper occurs naturally as a mix of two isotopes: Copper-63 with a mass of 62.930 amu and copper-65 with a mass of 64.928 amu. The percent abundance of copper-63 is 69.09%.
Calculate the atomic mass of copper.
Answers
Answer: 63.55
Explanation:
The attached chart shows the calculation. The orange line points to the % abundance of Cu-65, which is the difference of 100% less the % Abundance of Cu-65 (since there are only 2 isotopes).
The weighted average contribution of each istope is calculated (blue arrow) and then summed to find the atomic mass of copper.
For X + Y → XY, if [XY] is increasing at a rate 0.10 M s-1, predict the rate of depletion of both reactants.
Answers
If 12.2 kg of Al2O3(s), 57.4 kg of NaOH(l), and 57.4 kg of HF(g) react completely, how many kilograms of cryolite will be produced?
Answers
Explanation:
Write the balanced equation
Let's start off by writing the reaction for the formation of cryolite:
Al₂O₃ + 6NaOH + 12HF → 2Na₃AlF₆ + 9H₂O
Determine the limiting factor
moles = mass ÷ molar mass
moles of Al₂O₃ = 12200 g ÷ 101.96 g/mol = 119.65 mol
moles of NaOH = 57400 g ÷ 39.997 g/mol = 1435.11 mol
moles of HF = 57400 g ÷ 20.01 g/mol = 2868.57 mol
Since Al₂O₃ has the smallest number of moles in the reaction, it is the limiting factor. As such we will have to use the moles of Al₂O₃ to determine the moles of cryolite that will be produced.
Find the mole ratio between the limiting factor and the cryolite
The mole ratio of Al₂O₃ : Na₃AlF₆ based on the balanced equation is 1 : 2
∴ since the moles of Al₂O₃ = 119.65 mol
the moles of Na₃AlF₆ = 119.65 mol × 2 = 239.3 mol
Calculate the mass of the Cryolite
Mass cryolite = moles × molar mass
= 239.3 mol × 209.9 g/mol
= 50229.07 g
∴ kilograms of cryolite ≈ 50.23 kg
What was John Dalton's contribution to the development of the atomic theory?
A
Dalton recognized that tiny atoms combined to form complex structures.
B
Dalton recognized the presence of electrons around a nucleus.
C
Dalton recognized the presence of protons in the nucleus.
Answers
Answer:
A. Dalton recognized that tiny atoms combined to form complex structures.What type of chemical reaction is this?
Answers
Answer:
OXIDATION/REDUCTION
Explanation:
Ba has been transformed from a neutral atom to a +2 ion
O has been transformed from a neutral atom to a -2 ion
Use your own words to define Resultant:
Use your own words to define Resultant
Answers
Answer:
the outcome of something
Why are engineers called applied scientist?
Answers
Answer:
Applied science is a discipline that is used to apply existing scientific knowledge to develop more practical applications, for example: technology or inventions. In natural science, basic science (or pure science) is used to develop information to explain phenomena in the natural world.
Answer:
• Because engineers apply science and its theories into practical situation
Take an example of;
→ A generator: When creating a generator, electromagnetic induction theorem is applied. [ self and mutual inductance ]
→ A plane: The wings are made in considerance of Bernoulli principle and viscous drag
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The types of projection that are useful for making maps of the United States are called __________. (Choose 2)
Answers
Answer:
Mercator projection, geologic projection
WILL MARK AS BRAINLIEST IF CORRECT
The temperature of an enclosed gas at constant pressure changes from 400 K to 100 K atm. What happens to the volume of the gas?
a
The volume will increase to 4 times its original volume.
b
The volume will stay the same.
c
The volume will decrease to 1/2 of its original volume.
d
The volume will decrease to 1/4 of its original volume.
e
The volume will increase to 2 times its original volume.
Answers
Answer:
a
Explanation:
they are directly proportional. if one goes down the other goes up while pressure is constant
Phản ứng nào sau đây chuyển glucozơ và fructozơ thành một sản phẩm duy nhất?
A. Phản ứng với Cu(OH)2, t0. B. Phản ứng với dung dịch AgNO3/NH3. C. Phản ứng với H2/Ni, t0. D. Phản ứng với Na.
Answers
Answer:
Aaaaaaaaaaaaaaaassplee