K20
K = 1+
0 = 2-
K/0 = 1/2
the answer is K:O = 1:2
How many different principal quantum numbers can be found in the ground-state electron configuration of nickel?A) 2.B) 3.C) 4.D) 5.E) 6.
Answer:
C) 4.
Explanation:
Hello!
In this case, since the electron configuration of nickel at its ground-state, considering 28 as its atomic number and the number of electrons it has in one atom, is:
[tex]Ni^{28}:1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^8[/tex]
We can see it has four energy levels, 1, 2, 3 and 4, which are related to the following principal quantum number, that describes the energy of an electron in the atom and its most probable distance with respect to the nucleus.
Therefore, nickel has C) 4 different principal quantum numbers.
Best regards!
Draw conclusion: The density of water is 1.0 g/mL, or 1.0 g/cm². Look at the data in your table. How can you use the density of an object to predict whether it will sink or float?
(Data is above)
PLEASE HELP
Answer:
work out if it's either going to sink or float
Explanation:
this can be carried out by calculating the numbers
A gram sample of a KCl and KClO3 mixture was found to contain 0.00875 mol of KClO3. What is the percent by mass of KClO3 in the original mixture?
Answer:
53.5%
Explanation:
Step 1: Given data
Mass of the sample: we will suppose it is 2.00 g to show the procedureMoles of KClO₃: 0.00875 molStep 2: Calculate the mass corresponding to 0.00875 moles of KClO₃
The molar mass of KClO₃ is 122.55 g/mol.
0.00875 mol × 122.55 g/mol. = 1.07 g
Step 3: Calculate the percent by mass of KClO₃ in the mixture
We will use the following expression.
%m/m = mass of KClO₃/mass of the sample × 100%
%m/m = 1.07 g/2.00 g × 100%
%m/m = 53.5%
The percent by mass of KClO3 in the original mixture is 53.5%.
Calculation of the percentage:Since
The mass of the sample should be 2.00 g
Moles of KClO₃: 0.00875 mol
The molar mass of KClO₃ is 122.55 g/mol.
Now the mass is
= 0.00875 mol × 122.55 g/mol.
= 1.07 g
Now the percentage should be
= mass of KClO₃/mass of the sample × 100%
= 1.07 g/2.00 g × 100%
= 53.5%
hence, The percent by mass of KClO3 in the original mixture is 53.5%.
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Which would increase the reaction rate?
Check all that apply.
A. Stirring the reaction
B. Raising the activation energy
O C. Adding a catalyst
D. Raising the temperature
Answer:
adding a catalyst will increase the reaction rate.
Explanation:
im like 95% sure thats right.
Answer:
A. C. D
Explanation:
ap ex
in the reaction of magnesium metal with hydrochloric acid, how do you determine when the magnesium metal has reacted completely
Answer:
When there is no spark from the reaction
Explanation:
The reaction between the acid and the magnesium metal goes into completion when there is no more spark from the magnesium. Also, the magnesium would have totally disappeared into solution.
These physical observation marks the end of the reaction.
When Mg reacts with HCl hydrogen bubbles are released. The completion of the given reaction can be determined by the presence of bubbles above the HCl.
The reaction between HCl and Mg:[tex]\bold {Mg+ 2HCl\rightarrow MgCl_2 + H_2}[/tex]
In this reaction, Mg reacts with 2 moles of HCl to form 1 mole of Magnesium chloride and release hydrogen gas.
During reaction,
Magnesium slowly disappears as it reacts with HCl.The hydrogen gas is released during the reaction, bubbles can be observed.Therefore, the completion of the given reaction can be determined by the presence of bubbles above the HCl.
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Which sentence is punctuated correctly? A. I bought all the ingredients for dinner, eggs, tomatoes, macaroni, and cheese and told Molly to preheat the oven. B. I bought all the ingredients for dinner: eggs, tomatoes, macaroni, and cheese—and told Molly to preheat the oven. C. I bought all the ingredients for dinner eggs, tomatoes—macaroni, and cheese and told Molly to preheat the oven. D. I bought all the ingredients for dinner (eggs, tomatoes), macaroni, and cheese and told Molly to preheat the oven.
The sentence that has an accurate punctuation is found in (Option B).
What are punctuation marks?The punctuation marks are those marks that are use to make a piece of writing to have a complete meaning. A piece of writing will be meaningless if there are no attached punctuation marks.
The sentence that is correctly punctuated is; "I bought all the ingredients for dinner: eggs, tomatoes, macaroni, and cheese—and told Molly to preheat the oven."(Option B)
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liquid to gas require heat?
Answer:
yes
Explanation:
Answer:
yes
Explanation:
let's say you have ice, you put it on a pan then it heats up you get a liquid after a while it turns into a gas
A buffer is prepared by mixing 204.0 mL of 0.452 M HCl and 0.500 L of 0.400 M sodium acetate (NaC2H3O2):
Calculate the pH of the buffer.
How many grams of KOH must be added to 0.500 L of the buffer to change the pH by 0.15 units?
Answer:
pH = 4.89
0.6171g of KOH must be added
Explanation:
Sodium acetate reacts with HCl producing acetic acid as follows:
NaC2H3O2 + HCl → HC2H3O2 + NaCl
That means the moles added of HCl are moles of acetic acid produced and moles of acetate are initial moles - moles of HCl
Moles HCl = Moles acetic acid:
0.204L * (0.452mol / L) = 0.0822 moles acetic acid.
Initial moles sodium acetate:
0.500L * (0.400mol / L) = 0.200 moles
Moles sodium acetate:
0.200 moles - 0.0822 moles = 0.1172 moles sodium acetate
The pH of this buffer (Mixture of a weak acid and its conjugate base) is obtained using H-H equation:
pH = pKa + log [A-] / [HA]
Where pH is pH of the buffer,
pKa is pKa of the buffer (4.74 for acetic acid)
[A-] Moles of sodium acetate -Conjugate base-
And HA moles of acetic acid -Weak acid-
pH = 4.74 + log [0.1172 moles] [0.0822 moles]
pH = 4.89In 0.500L the moles of the buffer are:
0.500L * (0.200moles / 0.704L) = 0.142 moles of buffer
For a pH of 0.15 units more (4.89 + 0.15 = 5.04):
5.04 = 4.74 + log [Acetate] / [Acetic acid]
0.3 = log [Acetate] / [Acetic acid]
1.9953 = [Acetate] / [Acetic acid] (1)
And as:
0.142 = [Acetate] + [Acetic acid] (2)
Replacing (2) in (1):
1.9953 = 0.142 - [Acetic acid] / [Acetic acid]
1.9953 [Acetic acid] = 0.142 - [Acetic acid]
2.9953 [Acetic acid] = 0.142 moles
[Acetic acid] = 0.0474 moles of acetic acid must remain after the addition of KOH.
In the beginning, moles of acetic acid are:
0.0822 moles * (0.500L / 0.704L) = 0.0584 moles.
That means moles added of KOH (Equal to moles of acetic acid that react) are:
0.0584 moles - 0.0474 moles = 0.0110 moles of KOH
In grams (Molar mass KOH = 56.1g/mol):
0.0110 moles KOH * (56.1g/mol) =
0.6171g of KOH must be addedWhich statement best describes heating by conduction?
1. Sunlight travels through space without the aid of fluids or solids.
2. Air at the equator rises and sinks at the poles.
3. Air molecules touch the warm ground, heating them up.
4. Warm air rises and takes heat with it; eventually it cools and sinks.
(If you want brainliest please explain why the answer is that answer)
Answer:
It would be A. Air molecules touch the warm ground, Heating them up because conduction is when a source of energy touches something directly.
Answer:
3. Air molecules touch the warm ground, heating them up.
Explanation:
On a statistical basis,smoking a single cigarrette lowers your life expectancy by 642,000--------------------------.Pls answer this question
Thank you, also what are the options then I can help!
Which of the following are fair conductors and are always solid at room temperature?
1.Metals
2.Nonmetals
3.Metalloids
4.Ions
Answer:
Metalloids and ions
Explanation:
Mercury is not solid at room temperature. (Metals)
Many nonmetals aren't good at conducting electricity. Oxygen for example. (Nonmetals)
Metalloids are always solid at room temp and are fair conductors. (Metalloids)
Ions are same as metalloids. (Ions)
PLS GIVE BRAINLIEST
Which one is NOT true about chemical changes? *
Answer:
The second answer
Explanation:
Phase changes is an example of physical change because it only changes the substance's appearance.
Answer: 1 and 4 are the answers
Explanation: because when you mix a sub since and it will have a chemical change
1Water molecules can be ligands especially when they are bonded to
..........
A. alkaline earth metals
B. alkali metals
C. transition metals
D. group VII elements
Answer:c
Explanation:
find examples for each polysaccharides type.
Answer:
Glycogen: It is made up of a large chain of molecules. ...
Cellulose: The cell wall of the plants is made up of cellulose. ...
Starch: It is formed by the condensation of amylose and amylopectin. ...
Insulin: It is made up of a number of fructofuranose molecules linked together in chains.
Explanation:
The noble gases can be found in group/period ____
Answer:
group 18
Explanation:
The noble gases (Group 18) are located in the far right of the periodic table and were previously referred to as the "inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactive
Answer:group 18
Explanation
Choose ALL the answers that apply.
Sound _____.
travels in transverse waves
requires a medium to travel through
travels most slowly through solids
speeds up when temperature is increased
is changed into electrical impulses by the cochlea
Answer:
Speeds up when temperature is increased and can travel through a solid
Explanation:
2. Which of the following would produce a precipitate when mixed water (H20)?
A) HNO3
B) Br2
C) BaS
D) PbBr2
3.Given that the reaction below is a precipitation reaction, what is the missing symbol?
Li2CO3 (aq) + BaS (aq) - > LiOH (aq) + BaCo3 (?)
Answer: #2 : s, solid & #3 : PbBr2
Explanation:
In the reaction [tex]\rm Li_2CO_3 (aq) + BaS (aq)\rightarrow LiOH (aq) + BaCo_3 (?)[/tex] the missing symbol is s . The PbBr₂ will produce a precipitate when mixed water. Hence option D is correct.
What is chemical reaction?Chemical reaction is defined as a procedure that involves changing a substance's molecular or ionic structure, as opposed to changing its physical shape or undergoing a nuclear reaction. When atoms establish or break chemical bonds, chemical reaction take place. Reactants are the substances that begin a chemical reaction, while products are the compounds that are created as a result of the reaction.
Precipitation is defined as the mechanism by which water vapor in the atmosphere condenses and descends to the ground under the pull of gravity. Water vapor in the clouds condenses into increasing-sized droplets of water, forming precipitation. To replenish the water on the earth, precipitation is required. This world would be a vast desert if it didn't rain. Within an estuary, water level and water quality are impacted by the frequency and length of precipitation events.
Thus, in the reaction [tex]\rm Li_2CO_3 (aq) + BaS (aq)\rightarrow LiOH (aq) + BaCo_3 (?)[/tex] the missing symbol is s . The PbBr₂ will produce a precipitate when mixed water. Hence option D is correct.
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The ingredients of a soup include
1,500 grams of water, 350 grams of vegetables, and 210 grams of meat. What is the total mass of the soup?
Answer:
sopas
Explanation:
lagyan mo ng condense
There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, the total mass of the soup is 2,060gram.
What is solution?Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution. There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution.
mass of soup= mass of water+ mass of vegetables + mass of meat
mass of water=1,500 grams
mass of vegetables= 350 grams
mass of meat=210 grams
substituting all the values in the above equation, we get
mass of soup= 1,500 grams+ 350 grams + 210 grams
= 2,060gram
Therefore, the total mass of the soup is 2,060gram.
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what is the mass of silver that has a volume of 238mL? the density of silver is 10.5 g/cm^2
Explanation:
What volume of silver metal will weigh exactly 2500.0 g. The density of silver is 10.5 g/cm3. cm3 = 2500.0 g / 10.5 g/cm3 = 238 cm3
What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3? d = .85 g/cm3
Calculate the Molarity when a 6.11 mL solution of 0.1 H2SO4 is diluted with 105.12 mL of water
Molarity after dilution : 0.0058 M
Further explanationThe number of moles before and after dilution is the same
The dilution formula
M₁V₁=M₂V₂
M₁ = Molarity of the solution before dilution
V₁ = volume of the solution before dilution
M₂ = Molarity of the solution after dilution
V₂ = Molarity volume of the solution after dilution
M₁=0.1 M
V₁=6.11
V₂=105.12
[tex]\tt M_2=\dfrac{M_1.V_1}{V_2}=\dfrac{0.1\times 6.11}{105.12}=0.0058~M[/tex]
Arrange in order of decreasing atomic radii: Kr, K, Ge, Ca
Answer:
K > Ca > Ge > Kr
Explanation:
The elements given are all in the 4th period on the periodic table.
Kr, k, Ge, Ca;
Arranging their order from left to right;
K, Ca, Ge, Kr
Atomic radius is taken as half the of the inter-nuclear distance (d) between two covalently bonded atoms of non-metallic elements or half the distance between two nuclei in the solid state of metals.
Across the periodic table atomic radii decreases progressively from left to right. This is due to progressive increase in the nuclear charge (number of protons in the nucleus) without an attendant increase in the number of electronic shells.
From the left to right; decreasing radii;
K > Ca > Ge > Kr
Given the reaction _K(s) +_ Cl2(g) → _KCl(s) what is the amount of K, in grams, needed to completely react with 2 moles of Cl2(g)?
Answer:
156.4g K
Explanation:
I'm not sure if it is correct but I think it should be this
What do we know so far?: 2K + 1Cl2 -> 2KCl, 2 mol of Cl2
What are we looking for?: #g of K
What is the ratio of K to Cl2?: 2:1
Set up equation: 2molCl2 x [tex]\frac{2mol K}{1 mol Cl2}[/tex]
Cancel unwanted units: 2 x [tex]\frac{2mol K}{1}[/tex]
Answer we got: 2 x 2mol K = 4mol K
Converting moles to grams: 4 x 39.1 (molar mass of K) = 156.4g K
An example of a suspension is a ____
A)chemical b)heterogenous
c)homogenous d)salad
Answer:
b
Explanation:
suspension is the heterogenos solution
Suppose the Cu ions are produced by the reaction of 0.94 g of copper turnings with excess nitric acid. How many moles of Cu are produced?
Answer:
0.0148 moles
Explanation:
Solid copper is oxidized with HNO₃:
Cu + 4HNO₃ → Cu²⁺ + 2 NO₃⁻ + 2H₂O + 2NO₂
Where 1 mole of Cu produce 1 mole of Cu²⁺ when nitric acid is in excess.
Moles of Cu that react (Molar mass Cu = 63.546g/mol):
0.94g * (1mol / 63.546g) = 0.0148 moles of Cu
And moles of Cu²⁺ produced are also:
0.0148 molesCalculate the volume in milliliters of 1.57 M potassium hydroxide that contains 10.3 g of solute.
Answer:
[tex]V = 0.117 \ L[/tex]
General Formulas and Concepts:
Chem
Reading a Periodic TableWriting compounds and polyatomic ionsMolarity = moles of solute / liters of solutionExplanation:
Step 1: Define
1.57 M KOH (potassium hydroxide)
10.3 g KOH
Step 2: Define conversions
Molar Mass of K - 39.10 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H - 1.01 g/mol
Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol
Step 3: Convert
[tex]10.3 \ g \ KOH(\frac{1 \ mol \ KOH}{56.11 \ g \ KOH} )[/tex] = 0.183568 mol KOH
Step 4: Solve for Volume
Substitute: [tex]1.57 \ M=\frac{0.183568 \ mol}{x \ L}[/tex]Move x: [tex]x1.57 \ M=0.183568 \ mol[/tex]Isolate x: [tex]x=\frac{0.183568 \ mol}{1.57 \ M}[/tex]Evaluate: [tex]x=0.116922 \ L[/tex]Step 5: Check
We are given 3 sig figs. Follow sig fig rules.
[tex]0.116922 \ L \approx 0.117 \ L[/tex]
Which element would most likely have a chemical reactivity similar to bromine?
Answer:
Bromine is a very reactive element. While it is less reactive than fluorine or chlorine, it is more reactive than iodine. It reacts with many metals, sometimes very vigorously. For instance, with potassium, it reacts explosively.
Explanation:
Answer: Bromine is a high reactive element. While it is not as reactive as fluorine or chlorine, it is still more reactive than iodine. It reacts with many metals, and even sometimes very aggressively. For example, when mixed with potassium, it will explode.
Explanation:
What creates a weather front?
A weather front is a transition zone between two different air masses at the Earth's surface. Each air mass has unique temperature and humidity characteristics. Often there is turbulence at a front, which is the borderline where two different air masses come together. The turbulence can cause clouds and storms.
A microwave operates at 7.42 mm wavelength. How much energy is produced in Joules from 359 photons?
answer numerically using scientific notation with e and significant figures.
Answer:
[tex]E=9.62\times 10^{-21}\ J[/tex]
Explanation:
Given that,
The wavelength of a microwave is 7.42 mm or 0.00742 m
No. of photons, n = 359
We need to find the energy produced by this no of photons. It can be given by the formula as follows :
[tex]E=\dfrac{nhc}{\lambda}\\\\E=\dfrac{359\times 6.63\times 10^{-34}\times 3\times 10^8}{0.00742}\\\\=9.62\times 10^{-21}\ J[/tex]
or
[tex]E=9.62e^{-21}\ J[/tex]
So, the required energy is [tex]9.62\times 10^{-21}\ J[/tex].
Answer:
⬆️That guy deserves brainliest
Explanation:
How many molecules are present in 4.21 moles of HBr?
Answer:
The answer is
2.53 × 10²⁴ moleculesExplanation:
The number of molecules present can be found by using the formula
N = n × Lwhere n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 4.21 × 6.02 × 10²³
We have the final answer as
2.53 × 10²⁴ moleculesHope this helps you
Sulfite is similar to hydroxide in its behavior as a ligand: most sulfites are insoluble in water, but excess sulfite can result in the formation of a complex ion. Write the two equilibrium reactions of sulfite with the copper(II) ion that show this behavior.
Answer:
[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]
[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]
Explanation:
A ligand may be defined as a molecule or an ion or that binds to the central metal atom in order to form a more coordination complex. Sulfite is one such ligand and it behaves similarly as hydroxide as a ligand.
Now, according to the question, when we react copper with sulfite ion, it forms copper sulfite. The equation is
[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]
Now when excess of the sulfite ion is used in the reaction, we get a complex formation, which is shown by
[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]
The way the sulfite reacts is quite similar to hydroxide ion where they form a complex ion when hydroxide ion in excess is used in the reaction with metal cation.