element A it's valance number is 3 and element B it's valance number is 6 make it compound
Answer:
A2B
Explanation:
A = 3
B = 6
exchange valencies
A6B3
A2B
Which types of changes must follow the law of conservation of mass?
Both physical and chemical changes
Neither physical nor chemical changes
Only physical changes
Only chemical changes
Answer: both
Explanation:
An atom absorbs radiation. Select the possible changes this could have on the atom:
*it can change the atomic mass
*it can cause the atom to lose an electron
*it can cause the atom to become and ion
*it cause the atom to change element
Answer:
*it can cause the atom to become and ion
Calculate the energy of a photon emitted when an electron in a hydrogen atom undergoes a transition from =3 to =1.
Answer:
[tex]1.936\times 10^{-18}\ \text{J}[/tex]
Explanation:
[tex]R_h[/tex] = Rydberg constant = [tex]2.178\times 10^{-18}\ \text{J}[/tex]
[tex]n_i[/tex] = Initial shell = 3
[tex]n_f[/tex] = Final shell = 1
We have the relation
[tex]\Delta E=R_h(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2})\\\Rightarrow \Delta E=2.178\times 10^{-18}(\dfrac{1}{1^2}-\dfrac{1}{3^2})\\\Rightarrow \Delta E=1.936\times 10^{-18}\ \text{J}[/tex]
The energy of the photon emitted here is [tex]1.936\times 10^{-18}\ \text{J}[/tex].
Wine goes bad soon after opening because the ethanol ch3ch2oh in it reacts with oxygen gas o2 from the air to form water h2o and acetic acid ch3cooh , the main ingredient of vinegar. Calculate the moles of ethanol needed to produce 0.055mol of acetic acid. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.
Answer:
For producing 0.55 mole of acetic acid, 0.55 mole of ethanol is required.
Explanation:
The balanced equation for this reaction is
CH3CH2OH + O2 --> CH3COOH + H2O
As we can see in this equation, the ration of number of moles of acetic acid to the number of moles of ethanal is equal to [tex]1 : 1[/tex]
Hence, in order to produce one mole of acetic acid, 1 mole of ethanol is required.
Thus, for producing 0.55 mole of acetic acid, 0.55 mole of ethanol is required.
Suppose you have a mixture of iron filings, sand, and sugar and you want to separate the three. Fill in the materials you expect to see at each step as you perform the actions shown to separate them. The materials you may expect to see are: iron filings, sand, sugar, and sugar water.
Answer:
Explanation:
mixture of iron filings, sand, and sugar
First Step - Iron Fillings
Use a magnet to separate the iron fillings from the mixture. Due to magnetic properties of the iron fillings, the magnets would attract the iron fillings and separate it from the mixture.
Second step - Sand
Place the sand and sugar mixture in water. The sugar would dissolve in water and the sand easily separated by filtration.
Third step - Sugar and Sugar water
Boil the sugar water to remove the water and place in the refrigerator for crystallization of the sugar.
"Show a general equation for polymerisation"
Answer:
Polymerisation is the chemical process of monomers joining together to form polymers, often it takes many thousands of monomers to make a single polymer.
Explanation:
I gave brainlest:: answer this .....
A __________________ chemical equation shows that the same number of atoms in the reactants are also in the product.
balanced
rearranged
transferred
beautiful
answers this...i gave brainlest!!
Answer:
I hope I can help
Explanation:
I hope I can help you
5. If all the particles in a material are made up of
several smaller particles, and every larger particle
is identical, is the material a pure substance or
not? Explain your reasoning.
Answer:
No. Because a pure substance, no matter if an element, compound, it can only contain one kind of particle .
Explanation:
what is 20+9-10+67=?
Answer:
86
Explanation:
20 plus 9 equals 29 minus 10 equals 19 plus 67 equals 86
Answer:
86
Explanation:
20+9=29
29-10=19
19+67=86
how many moles are in 6.31x10^24 C atoms
Answer:
Explanation:
1 mol of any chemical is 6.02 * 10^23
x mol of any chemical is 6.31 * 10^24
You should look at this before you put it in your calculator. You should think roughly 10.
Now you can set it up as a proportion
1/x = 6.02 * 10^23/6.31 * 10^24 Cross multiply
6.02 * 10^23 x = 1 * 6.31 * 10^24 Divide by 6.02 * 10^23
x = 6.31 * 10^24 / 6.02 * 10^23
x = 10.48 mols.
An increase in the volume of a substance because of an increase in temperature is called
Answer:
Its called contraction.
Explanation:
Calculate the number of moles in 2.67 g of carbon trihydride
Answer:0.178 moles
Explanation: carbon trihydride seems to be an unusual name for the methyl group CH3–
ionic wt 15
moles = 2.67/15 = 0.178
New rocks are heavier than old rocks.
with 24.1 moles of P4O10 how many moles of H3PO4 could be made
How many grams are there in 3.4 x 10^24 atoms of He?
Group of answer choices
2.07
5.7 g
0.57 g
20.7
Given :
Number of He atoms, [tex]n = 3.4\times 10^{24}[/tex] atoms.
To Find :
How many grams are their in given number of He atoms.
Solution :
We know, molecular mass of He is 4 g. It means that their are [tex]6.022 \times 10^{23}[/tex] atoms in 4 g of He.
Let, number of gram He in [tex]3.4\times 10^{24}[/tex] atoms is x , so :
[tex]x = \dfrac{3.4\times 10^{24}}{6.022\times 10^{23}}\times 4\\\\x = $$22.58\ g[/tex]
Therefore, grams of He atoms is 22.58 g .
Calculate the mass (in g) of solute needed to prepare a solution with the given concentration and volume.
Sea water has a concentration of approximately 0.60 M sodium chloride. How much
sodium chloride is dissolved in 1.00 L of solution?
Coke has a concentration of 0.342 M. What mass of sugar (in g) is dissolved in a 2-L
bottle of coke?
What volume of concentrated nitric acid (15.8 M) is needed to prepare 4.0 L of a 2.0 M solution?
What volume of 9.0 M copper (II) sulfate stock solution is needed to prepare 3.0 L of a 5.0 M
solution?
Answer:
1. 35g NaCl.
2. 234g sugar.
3. 0.506L of concentrated nitric acid are needed.
4. 1.67L of 9.0M copper (II) sulfate are needed
Explanation:
Molarity is defined as the ratio between moles of solute and the volume of the solution.
1. 1.00L * (0.60mol / L) = 0.60 moles NaCl are dissolved
To convert moles to mass we must use its molar mass:
0.60mol NaCl * (58.44g/mol) =
35g NaCl
2. 2L * (0.342mol / L) = 0.684 moles Sugar = moles sucrose
0.684 mol * (342.30g / mol) = 234g sugar
3. 4L of a 2.0M are:
4L * (2.0mol/L) = 8moles
8mol * (1L / 15.8mol) = 0.506L of concentrated nitric acid are needed
4. 3.0L * (5.0 mol / L) = 15.0 moles copper (II) sulfate.
15.0mol * (1L / 9.0mol) = 1.67L of 9.0M copper (II) sulfate are needed
how many lbs are in 60 oz
Answer:
3 pounds 13 ounces
Explanation:
Math
Answer:
3.75
Explanation:
2) Which liberates the most energy?
A) F(g) + e ➡️ F-(g)
B) N(g) +e- ➡️ N-(g)
C) O(g) +e ➡️ O-(g)
D) C(g) +e ➡️ C-(g)
Answer: [tex]F(g)+e^-\rightarrow F^-(g)[/tex]
Explanation:
Electron gain enthalpy is defined as energy released on addition of electron to an isolated gaseous atom.
The amount of energy released will be maximum when the tendency to attract electrons is maximum. As flourine has atomic number of 9 and has electronic configuration of 2,7. It can readily gain 1 electron to attain stable noble gas configuration and hence liberates maximum energy.
[tex]F(g)+e^-\rightarrow F^-(g)[/tex]
1 point
If the element Lithium (Li) were to bond with the element Sulfur (s), what
type of bond can you predict will be formed and why?*
A. Covalent-Li and S are two nonmetals
B. Covalent-Li is a metal and S is a nonmetal
C. Ionic-Li and S are two nonmetals
D. Ionic-Li is a metal and S is a nonmetal
Answer:
C. Ionic-Li and S are two nonmetals
1.a)concentrated sulphuric acid reacts with ethanol to produce ethene
(i) state the conditions for the reaction
.......................................................................
write the equation of the leads to formation of ethene In (a) (i) above.
.....................................................................................
state the property of sulphuric acid shown in reaction (a)(ii)
...................................................................................
Answer: a) Temperature of [tex]170^0C[/tex]
b) [tex]C_2H_5OH\stackrel{conc H_2SO_4, 170^0C}\rightarrow C_2H_4+H_2O[/tex]
c) dehydrating agent
Explanation:
Ethanol is heated with an excess of concentrated sulfuric acid at a temperature of 170°C to produce ethene.
The balanced chemical reaction is:
[tex]C_2H_5OH\stackrel{conc H_2SO_4, 170^0C}\rightarrow C_2H_4+H_2O[/tex]
Here concentrated sulfuric acid removes a water molecule from ethanol and thus acts as a dehydrating agent.
An atom of the element chromium has an atomic number of 24 and a mass number of 52. How many electrons are in an uncharged atom of chromium?
0
24
28
52
Answer:
24
Explanation:
In an uncharged atom, the number of protons is always equal to the number of electrons. For example, carbon atoms include six protons and six electrons, so carbon's atomic number is 6.
Similarly, since an atom of chromium contains 24 protons, it also contains the same amount of electrons, which is 24.
Answer:
24 is your answer
Explanation:
why is productivity greatest near the ocean's surface?
Answer:
Sunlight penetrates the top layers of the ocean, so photosynthesis occurs there. ... Upwelling brings nutrients to the surface.
What is a reactant?
A- Solid particles that have been separated from a solution
B- A substance that has the ability to be dissolved by a solvent
C- A mixture in which a solid and a liquid or two liquids are mixed occurs
D- The substance present before a chemical reaction occurs
Answer:
it is D
Explanation:
because it is a substance that participants in a chemical reaction.
Identify the products in the reaction HCI + NaOH → NaCl + H20.
A. HCI, NaOH, NaCl, and H2O
B. HCl and NaOH
C. NaCl and H20
D. NaOH and H20
The products in the reaction HCI + NaOH → NaCl + H20, are C. NaCl and H20.
How are these the products ?The reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) is a neutralization reaction, which means that it produces a salt and water. In this case, the salt is sodium chloride (NaCl) and the water is H2O.
The other options are not correct because they do not include all of the products of the reaction. Option (A) includes HCl and NaOH, but it does not include H2O. Option (B) only includes HCl and NaOH. Option (D) only includes NaOH and H2O.
In conclusion, option C is correct.
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write the balanced equation for the formation of carbon dioxide.
write and balance the cellular respiration equation of glucose compared with the photosynthesis reaction in the terms of reactants products energy flow in the significance of each.
Answer:
Explanation:
.
If 1 g of radium-226 has an activity of 1 curie, what is the activity of 2 g of radium-226? 1 curie 2 curies 4 curies 10 curies
Answer:
2 curies
Explanation:
This is actually pretty easy to explain.
The Radium-226 which is an isotope of the radium, have an activity of curie. This is basically used in radioactivity of certain elements.
As in both cases we have Radium -226 and we are only varying the mass of the Radium, then, we can just do a rule of 3 to calculate this:
1 g Ra-226 --------> 1 Curie
2 g Ra-226 --------> X Curie
Solving for X:
X = 2 g * 1 Curie / 1 g
X = 2 Curies.You can also see this by taking 2 grams of Ra per separate. On one side you have 1 g of Ra-226 and on the other side, you have another 1 g of Ra-226. Both have 1 Cury of activity. If you put both on the same side, you will have 1 Cury of 1 isotope plus 1 cury of the other isotope, final result? 2 curies.
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