Answer:
[Ar] 4s2
Explanation:
The noble gas that comes before Ca is Ar, so that's what you'll use for the noble-gas shorthand part of it. Ca has two additional electrons in the 4s orbital, hence the 4s2.
The ground state electronic configuration of calcium using noble gas short hand notation is [Ar]4s².
What is noble gas short hand notation ?Noble gas short hand notation comprises of the symbol of the last noble gas which is prior to the concerned atom which is followed by the configuration of the electrons which remains.
This notation helps in shortening of electronic configuration which is otherwise huge for elements with high atomic numbers.This is possible cause it uses the preceding noble gas configuration which accounts for that many electrons and the remaining electrons are filled in the next higher sub shell.
For calcium, preceding noble gas is argon which accounts for 18 electrons and for remaining two electrons they are placed in 4s sub shell thus making the total count of electrons to 20.
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True or False: With a given number of moles of solvent, the solution will always have the same concentration
Answer:
Its true
Explanation:
Hope it helps, have a great day!!!
Environments have changed over millions of years. Which of these would be best for a scientist to study when investigating these environmental changes?
A. volcanic deposits
B. weather forecasts
C. fossil records
D. ocean currents (There is no science subject so ima put mathematics)
Answer:
c
Explanation:
fossil records
How many moles of carbon dioxide gas occupy a volume of
81.3 L at 204 kPa and a temperature of 95.0 °C?
mol CO2
Answer:
5.42
Explanation:
I used a calculator
Answer: 5.42 mol CO2
Explanation: Uses idea gas law
What would a curve with the shape of an isoceles triangle indicate?
Calculate the percent error, with correct sig figs, in the atomic weight if the mass of a Zn electrode increased by 0.3681 g and 6.514x10-3 moles of Zn was produced. Select the response with the correct Significant figures. You may assume the molar mass of elemental zinc is 65.38 g/mol. Refer to Appendix D as a guide for this calculation.
Answer:
the percent error is -13.5%
Explanation:
Given the data in the question;
Exact atomic weight = 65.38 g/mol
For approx
increased mass = 0.3681 g
moles = 6.514 x 10⁻³
we know that; moles = mass / (Atomic mass )
so
Atomic mass_[tex]_{approx[/tex] = mass / moles
Atomic mass_[tex]_{approx[/tex] = 0.3681 / 6.514 x 10⁻³
Atomic mass_[tex]_{approx[/tex] = 56.509
so approx atomic weight = 56.51 g/mol
we know that;
% error = ( [approx - exact] / exact ) × 100
we substitute
% error = ( [56.51 - 65.38] / 65.38 ) × 100
% error = (-8.87 / 65.38 ) × 100
% error = ( -0.1356684 ) × 100
% error = -13.5%
Therefore, the percent error is -13.5%
How many moles of C2H2 are required to produce 0.60 mol of H2O?
Express your answer to two significant figures and include the appropriate units.
Answer:
0.60 moles
Explanation:
From the reaction:
[tex]2C_2H_2 + 5O_2 \to 4CO_2+2H_2O[/tex]
From above, Only 2 moles of CH2CH2 are required to produce 2 moles of water (H_2O).
As such, 0.6 moles of H2O will require:
x (CH2CH2) × 2 moles of (H_2O) = 0.6 moles (CH2CH2) × 2 mole of (H_2O)
x mole of (CH2CH2) = 0.60 moles
∴
0.6 moles of H2O will require 0.60 moles of CH2CH2
briefly describe how the pH of a colourless solution could be measured using a universal indicator
Answer:
Universal indicator can show us how strongly acidic or alkaline a solution is, not just that the solution is acidic or alkaline. This is measured using the pH scale , which runs from pH 0 to pH 14.
Explanation:
~Hope this helps
hellooooooooooooooooooooo
Answer:
hiiiiiiiiiiiiiiiiiiiiiiiii THANK YOU SO MUCH FOR THE POINT
Describe two signs that show that a chemical reaction happens when magnesium
burns in air.
Answer:
When magnesium burns in air, the oxygen in the air reacts with magnesium metal to produce magnesium oxide.
Magnesium burns in oxygen present in the air to produce magnesium.
How many grams of K2Cr2O7 can be dissolved at 279 grams of water at 90°C?
Answer:
How many grams of K2Cr2O7, are soluble in 100 g of water at 95 ºC? Solubility Curve DRAFT. 10th - 12th grade. 3326 times. Chemistry. 63% average accuracy. 3 years ago ... When 20 grams of potassium chlorate, KClO 3, is dissolved in 100 grams of water at 80 ºC, the solution can be correctly described as: answer choices . supersaturated. saturated.
Explanation:
Question
How much of 3 M NaOH will be required to make 100 mL of 0.05 M NaOH?
Select the correct answer below:
5 mL
1.7 mL
0.15 mL
30 mL
Answer:
1.7 mL
Explanation:
start with formula M1V1=M2V2
then plug in values (3)V1=(100)(.05) and solve for V1
V1= 1.66
According to molar concentration, 1.7 ml of of 3 M NaOH is required to make 100 ml of of 0.05 M NaOH.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.
In case of 2 solutions, molarity is determined as, M₁V₁=M₂V₂
Substitution of values gives, V₁=0.05×100/3=1.7 ml.
Thus, 1,7 ml of 3 M NaOH will be required to make 100 mL of 0.05 M NaOH.
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Water which has soaked into the ground is known as
Identify an alkene and carboxylic acid using primary observations
If the unknown substance decolorize bromine water, it is an alkene. If it does not, litmus paper is used to test it. If the paper turns red, then the substance may be a carboxylic acid, and the reaction with sodium carbonate serves as additional confirmation. It is not a carboxylic acid if it does not react with sodium carbonate. A substance is not an alkene or a carboxylic acid if it does not decolorize bromine water and is not acidic.
What is the flowchart for identification of an alkene and carboxylic acid?The following flowchart can be used to recognize an alkene and a carboxylic acid:
1. Start with the hypothetical unknown substance.
2. Use bromine water to test the substance.
a. An alkene is a substance that discolors bromine water.
b. Move on to the following stage if the compound does not lighten bromine water.
3. Use universal indicator paper or litmus paper to test the chemical.
a. The substance might be a carboxylic acid if it is acidic and causes the paper to turn red.
b. Go to the following step if the chemical is not acidic.
4. Use sodium carbonate to evaluate the substance.
a. A substance is a carboxylic acid if it reacts with sodium carbonate to release carbon dioxide gas.
b. The chemical is not a compound if it does not react with sodium carbonate.
Therefore, if the unknown substance decolorize bromine water, it is an alkene. If it does not, litmus paper is used to test it. If the paper turns red, then the substance may be a carboxylic acid, and the reaction with sodium carbonate serves as additional confirmation.
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Your question is incomplete, most probably the complete question is:
TASK 2 - Pass 2B.P4 Identify an alkene and carboxylic acid using primary observations. To achieve 2B.P4, learners should follow guidance to identify an alkene and a carboxylic acid (for example, ethanoic acid) from primary observations. Learners will be expected to identify an alkene in the way described in 1B.4. For ethanoic acid this is by its pH and its reaction with sodium carbonate. The guidance given to the learners could be in the form of a flowchart.
How many moles are in 8.7 x 104 atoms of oxygen?
Question 2
Which of the following correctly describes what a mutation is?
A). A change in the DNA code of an organism
B). A change to a gene of an organism
C). A change to the nucleotide sequence
D).All the above
Answer:
d
Explanation:
a mutation is the variation of a norm, a mutation can alter any organism in any way
intermolecular dehydration of alkanols will gives what?
Answer:
One way to synthesize alkenes is by dehydration of alcohols, a process in which alcohols undergo E1 or E2 mechanisms to lose water and form a double bond. The dehydration reaction of alcohols to generate alkene proceeds by heating the alcohols in the presence of a strong acid, such as sulfuric or phosphoric acid, at high tempera (sorry if this is wrong )
How many moles of iron will be produced from 6.20 moles of carbon monoxide reacting with excess iron oxide
Explanation:
..........................m
A student mixes 50.0 mL of 1.00 M Ba(OH)2 with 72.8 mL of 0.375 M H2SO4.
a)Calculate the mass of BaSO4 formed.
b)Calculate the pH of the mixed solution.
Answer:
The correct answer should be 12.72 pH of the mixed solution and 9.94g mass of solid BASO4 formed.
The molecules of Ba(OH)2 are : 1.00M x 0.05L = 0.05 ( moles )
The molecules of H2SO4 are : 0.494M x 0.0864L = 0.0426816
Ba(OH)2 + H2SO4 ----> BaSO4 + 2 H2O
0.0426816<--- 0.0426816
The mixed solution is Ba(OH)2 with 0.05 - 0.0426816 = 0.0073184
The concentration of mixed solution is : 0.0073184 : ( 0.05 + 0.0864 ) = 0.054 M
The pH of mixed solution is 14 - -log[0.054] = 14 - 1.27 = 12.73 PH
And the mass of BaSO4 is 0.0426816 x ( 137 + 32 + 16 x 4 ) = 9.94 gams.
In the front of the room, there is a bottle that contains a 32.00 g sample of sulfur. This is
1 mole of sulfur. Estimate how many atoms are in the bottle.
Which two changes would make this reaction product-favored? 3H2 + N2 ⇄ 2NH3 + energy  A. Decreasing the pressure  B. Increasing the temperature  C. Increasing the pressure  D. Reducing the temperature
Answer:C and D
Explanation:Just did it
Increasing the pressure and Decreasing the temperature are the two changes would make this reaction product-favored.
What is Equilibrium ?It is a state when a reaction is reversible and both forward and reverse reaction occur simultaneously at the same rate .
In the process of manufacture of Ammonia , both forward and reverse reaction are taking place
N₂(g) + 3H₂ (g) → 2NH₃ (g)
2NH₃(g) → N₂ (g) + 3H₂ (g)
when these reaction occur at same rate , the state is called equilibrium and is represented by
N₂ (g) + 3H₂(g) ⇔ 2NH₃(g) +Heat
As we can see from the equation , heat is produced in the forward reaction so if we increase the temperature the reverse reaction will be favored ,
On decreasing temperature the reaction will become product favored .
While on increasing the Pressure the manufacture of Ammonia increases.
Therefore Option C and Option D are the two changes would make this reaction product-favored.
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What are two main ways that water is being polluted or wasted
Answer:
Chemical waste from factories is sometimes dumped into rivers and lakes, or directly into the ground. Pesticides (chemicals that kill insects) applied to farmland enter surface water and groundwater, often in large quantities. Leaks from underground storage tanks for liquids like gasoline go directly into groundwater.
Explanation:
Hope it helps! Correct me if I am wrong!
Im sure about my answer!
If you dont mind can you please mark me as brainlest?
A chromophore is:______
a. an unsaturated organic functional group that absorbs ultraviolet or visible radiation.
b. a biochemical species, such as NADH, that strongly absorbs ultraviolet or visible radiation.
c. an ion or complex of elements from the first two transition series that absorbs visible radiation.
d. a molecule that contains an electron-donor group bonded to an electron-acceptor. When radiation is absorbed, an electron is transferred from the donor to an orbital of the acceptor.
a. an unsaturated organic functional group that absorbs ultraviolet or visible radiation.
Hope this helps :D
Based on the picture of the map, why does Buenos Aries have a higher ocean surface temperature than Cape Town even though they have the same latitude?
A sample of gas initially has a volume of 2.25 L at 350 K and a pressure of 1.75 atm. What will be sample pressure if the volume is
changed to 1.00 L and the temperature to 750 K
O 3.75 atm
O 1.84 atm
O 3.94 atm
O 8.44 atm
O 0.119 atm
Answer:
8.44 atm
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 2.25 L
Initial temperature (T₁) = 350 K
Initial pressure (P₁) = 1.75 atm
Final volume (V₂) = 1 L
Final temperature (T₂) = 750 K
Final pressure (P₂) =?
The final pressure of the gas can be obtained as illustrated below:
P₁V₁/T₁ = P₂V₂/T₂
1.75 × 2.25 / 350 = P₂ × 1 / 750
3.9375 / 350 = P₂ / 750
Cross multiply
350 × P₂ = 3.9375 × 750
350 × P₂ = 2953.125
Divide both side by 350
P₂ = 2953.125 / 350
P₂ = 8.44 atm
Thus, the final pressure of the gas is 8.44 atm.
Identify the following for an atom with 8 protons, 8 electrons, and 7 neutrons.
a. Atomic number:
b. Mass number:
c. Nuclear Notation:
d. Hyphen Notation:
please help
Answer:
i thinks its a. but iam not sure
How can radioisotopes help in promoting clean technology in the mitigation of the effect of climate change? What are the challenges in the application of this technology?
Forget about mitigating climate change. Our planet has been warming nicely for the last three hundred years or more, and is a lot more productive and comfortable to live on than it was back then. All we have to do is not stuff it up.
HOPE IT HELPS U
FOLLOW MY ACCOUNT PLS PLS
What volume in
L
of a 0.724 M Nal solution contains 0.405 mol of Nal ?
Answer:
0.559 L
Explanation:
Step 1: Given data
Moles of sodium iodide (n): 0.405 mol
Molar concentration of sodium iodide (M): 0.724 M (0.724 mol/L)
Step 2: Calculate the volume of solution (V)
The molarity is equal to the moles of solute divided by the liters of solution.
M = n/V
V = n/M
V = 0.405 mol/(0.724 mol/L) = 0.559 L
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This is a freebie for anyone for one get the crown
Answer:
hhh
Explanation:
Can somebody please help me!!!
Answer:
force are called roll
Explanation:
force your answer give me five Points
Answer:
friction
Explanation:
The other terms honestly just don't make any sense in this context. Round objects experience less friction, since they have less of their surface touching the ground at a time. Imagine a bowling bowl: only a small part of the ball is ever touching the ground at one instant. Now imagine a waffle: almost all of the surface is touching the ground.
Which describes how technology has changed society?
A. There is less food available to people.
B. People live longer than they used to
O C. It is more difficult to move goods
O d. It is hard for people to communicate
Answer:
B. People live longer than they used to
Explanation:
None of the other answers are correct.