IN 4Ca(OH)2 how many atoms of calcium.
This substance contains 4 atoms. Ca = 1. O = 1. H = 2 because H2 means two atoms of the substance it comes after.
The "clusters" of Democritus are like what kind of material
that we know of today?
Element X has two isotopes. One has a mass of 45.0 amu and is 45.0% abundant. The other has a mass of 47.0 amu and is 55.0% abundant. What is the average atomic mass of element X?*
0 46.1 amu
O 36.5 amu
0 43.8 amu
0 48.9 amu
The average atomic mass of element X that has two isotopes (one of 45.0 amu mass and 45% abundance and the other of 47.0 amu mass and 55.0% abundance) is 46.1 amu (option 1).
The average atomic mass (A) of element X can be calculated as follows:
[tex] A = m_{1}\%_{1} + m_{1}\%_{1} [/tex] (1)
Where:
m₁: is the mass of isotope 1 = 45.0 amu
m₂: is the mass of isotope 2 = 47.0 amu
%₁: is the abundance percent of isotope 1 = 45.0 %
%₂: is the abundance percent of isotope 1 = 55.0 %
Hence, the average atomic mass is (eq 1):
[tex] A = m_{1}\%_{1} + m_{1}\%_{1} = 45.0 amu*45.0\% + 47.0 amu*55.0\% = 45.0 amu*0.45 + 47.0 amu*0.55 = 46.1 amu [/tex]
Therefore, the average atomic mass of element X is 46.1 amu (option 1).
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15.24. Calcium hydroxide, also known as slaked lime, is used in industrial processes in which low concentrations of base are required. Only 0.16 g of Ca(OH)2 dissolves in 100 mL of water at 25°C. What is the concentration of hydroxide ions in 250 mL of a solution containing the maximum amount of dissolved calcium hydroxide?
The concentration of the hydroxide ions, OH¯ in 250 mL of the solution containing the maximum amount of dissolved calcium hydroxide is 0.01728 M
We'll begin by calculating the number of mole of in 0.16 g of Ca(OH)₂. This can be obtained as follow:
Mass of Ca(OH)₂ = 0.16 g
Molar mass of Ca(OH)₂ = 40 + 2[16 + 1] = 74 g/mol
Mole of Ca(OH)₂ =?Mole = mass / molar mass
Mole of Ca(OH)₂ = 0.16 / 74
Mole of Ca(OH)₂ = 0.00216 mole Next, we shall determine the molarity of the stock solution of Ca(OH)₂.Mole of Ca(OH)₂ = 0.00216 mole
Volume = 100 mL = 100 / 1000 = 0.1 L
Molarity of Ca(OH)₂ =?Molarity = mole / Volume
Molarity of Ca(OH)₂ = 0.00216 / 0.1
Molarity of Ca(OH)₂ = 0.0216 MNext, we shall determine the molarity of the diluted solution. This can be obtained as follow:Volume of stock solution (V₁) = 100 mL
Molarity of stock solution (M₁) = 0.0216 M
Volume of diluted solution (V₂) = 250 mL
Molarity of diluted solution (M₂) =?M₁V₁ = M₂V₂0.0216 × 100 = M₂ × 250
2.16 = M₂ × 250
Divide both side by 250
M₂ = 2.16 / 250
M₂ = 0.00864 MThus, the molarity of the diluted solution is 0.00864 M
Finally, we shall determine the concentration of the hydroxide ions, OH¯ in the diluted solution. This can be obtained as follow:Ca(OH)₂(aq) —> Ca²⁺(aq) + 2OH¯(aq)
From the balanced equation above,
1 mole of Ca(OH)₂ contains 2 moles of OH¯
Therefore,
0.00864 M Ca(OH)₂ will contain = 2 × 0.00864 = 0.01728 M OH¯
Thus, the concentration of the hydroxide ions, OH¯ in 250 mL of the solution containing the maximum amount of dissolved calcium hydroxide is 0.01728 M
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14. The following are a list of the four parts of John Dalton's atomic theory Indicate which of
the parts have been modified and why.
1. All matter is made of tiny, indivisible particles called atoms
2. All atoms of an element are identical and all atoms of different atoms are different
3. Atoms of one element cannot be turned into atoms of another element.
4. All atoms combine with one another in fixed whole number ratios.
Answer:
1
all matter is made of tiny particles called atom
The lower the pressure, the lower a liquid’s boiling point is. Water actually boils much faster at the top of a mountain where air pressure is lower. Without pressure water in the body begins to boil. What do you think will happen to your body as blood, saliva, and other fluids boil?
Answer:
The lower the pressure, the lower a liquid's boiling point is. That's why water boils much faster at the top of a mountain than it does at the bottom. In space, there is no pressure. So the boiling point could easily drop to your body temperature.
mark as a brainlist plz.
In an experiment combining vinegar and baking soda, gas is given off. In this
chemical reaction, the vinegar and baking soda are…
A elements
B products
C suspensions
D reactants
Answer:
The correct answer is D hope this helped :3Answer:
(D)
Explanation:
In the reaction between vinegar and baking soda, the reactants are vinegar (acetic acid) and baking soda (sodium bicarbonate). The products are sodium acetate, water, and carbon dioxide gas.
.
You should be able to
these groups on the periodic table, and know their
properties.
Answer:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties.
Explanation:
I HOPE NAKATULONG PO AKO:)PA BRAINLEST NLNG PO SANA:(ANSWER ASAP PLZ???????????????????????????????????
Answer:
The answer should be A
Explanation:
Answer:
Leaving a Copper penny in vinegar until it turns green
Explanation:
the others are physical changes. when copper penny is put in vinegar, a reactive oixde layer is formed which is green in colour. namely, Cu(II) acetate.
The green growing on the penny of copper and the rust forming on the nail of iron are chemical changes. Boiling away salt water, scraping iron filings from a mixture of sand with a magnet, and breaking a rock with a hammer, are physical changes.
Water, made of 1 oxygen atom bonded with 2 hydrogen atoms, is what
Answer:
It is a water molecule.
Explanation:
A water molecule consists of two atoms of hydrogen linked by covalent bonds to the same atom of oxygen. Atoms of oxygen are electronegative and attract the shared electrons in their covalent bonds.
Answer:
A water molecule is an example of a molecule created through covalent bonding. Water is made up of one oxygen atom and 2 hydrogen atoms, hence the chemical symbol H2O. A hydrogen atom is made up of 1 proton at its core and 1 electron that revolves around the core in a three-dimensional orbit.
Explanation:
how do lone pairs of electrons influence the structure of molecules?
Answer:
lone pairs and bonds both repulsive each other
Explanation:
therefore bond angles will be changed that leads to the original geometry in nature
What are the most common sources of nitrates that lead to unhealthy water systems
Answer:
Sources of nitrate that can enter your well include fertilizers, septic systems, animal feedlots, industrial waste, and food processing waste.
In a movable pulley system, where does the other effort come from?
Answer:
In a movable pulley system, where does the other effort come from? is carried by this end of the rope. This means that the structure (ceiling) does half the effort.
Explanation:
What two factors must be held constant for density to be a constant ratio?
Answer:
Temperature and Pressure
Explanation:
Temperature and pressure cause change in volume.
So any change in volume will alter the ratio of density as given by equation of density.
Density = mass/ volume
Change in volume will alter the ratio.
Kindly mark it branliest if the answer is little bit satisfying.
What is the frequency of red light with a wavelength of 645 nm?
Answer:
4.64E14
Explanation:
First convert 645 nm to m = 6.4500E-7m. The equation for finding v with these values is the speed of light/wavelength. so 2.998E8/6.4500E-7m.
so your v or frequency would equal 4.64E14
Fun fact you know this is visible light because the visible light range is within the E14 range.
When does an electrically charged object attract another object?
A. When one object is far away from the other
B. When each object is negatively charged
C. When the objects are oppositely charged
D. When each object is positively charged
Answer:
C. When the objects are oppositely charged
Explanation:
Electrostatic interactions are commonly observed whenever one or more objects are electrically charged. Two oppositely-charged objects will attract each other. A charged and a neutral object will also attract each other. And two like-charged objects will repel one another.
From Bing, this is not my work
Answer:C
Explanation:
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC! lol i think its c
what does the theory of plate tetonics state
Answer:
Plate tetonics theory is the idea that different tectonic plates, are constantly moving and changing the surface of our Earth. They can move in three ways, convergent, divergent, and transform. Seafloor Spreading is like an example of divergent movement. When the plates diverge from each other it can create various changes such as creating a new sea floor. You can use seafloor spreading as an example of the plate tetonics theory.
Explanation:
draw the product of the sn2 reaction and indicate stereochemistry. write the inorganic product in the answer palette.
SN2 reaction proceeds with inversion of configuration at the reacting carbon atom. The product has a different configuration at this carbon atom from the product.
SN2 reaction is a short form for substitution nucleophilic bimolecular reaction. It is a synchronous reaction in which the leaving group departs at the same time as the nucleophile attacks in a single transition state.
Recall that SN2 reaction proceeds with inversion of configuration hence the product has a different configuration at the reacting carbon atom from the product. The inorganic product in this reaction is HI. The organic product is shown in the image attached to this answer.
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what is the polystyrene?
Answer:
Polystyrene is a versatile plastic used to make a wide variety of consumer products.
Explanation:
Answer:
polystyrene, a hard, stiff, brilliantly transparent synthetic resin produced by the polymerization of styrene. Styrene is obtained by reacting ethylene with benzene in the presence of aluminum chloride to yield ethylbenzene.
Explanation:
in other words its a plastic
A mixture of hydrogen, nitrogen, and water vapor has a total pressure of 864 mmHg. The partial pressure of hydrogen is 220 mmHg and that of nitrogen is 410 mmHg. What is the partial pressure of water vapor?
Answer:
As per Dalton's law of Partial pressure,
The total pressure of a mixture of gases is equal to sum of partial pressure of individual components of the mixture.
So,P=P_H+P_N+P_WP=P
H
+P
N
+P
W
\implies 864\ mm=220\ mm+410\ mm+P_W\implies⟹864 mm=220 mm+410 mm+P
W
⟹ P_W=864-630=234P
W
=864−630=234 mm of Hg.
Explanation:
"The partial pressure of water vapor is 234 mm Hg."
What is partial pressure?
The force that a gas exerts is known as partial pressure. The total pressure of a mixture of gases is equal to the sum of their partial pressures.
Partial pressure can be calculated by using the formula: [tex]P_{Total} =P_{N} +P_{H} +P_{H}[/tex]
Puts the value of given data in above equation.
[tex]Px_{W} =864-410-220\\\\= 234 mm Hg[/tex]
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An atom has 17 protons and 18 neutrons.
Which symbol represents that atom, including its mass number?
Answer:
Cl
Explanation:
cl has mass number 35 and its atomic number is 17 so number of proton =atomic number 17 and number of neutron is =mass number -number of proton =35-17 =18
From the following which is not an ore
a.bauxite
b.haematite
c.calamine
d.cyolite
Answer: d. Cyolite
Explanation:
a.bauxite - Aluminum ore ✅
b.haematite - Iron ore ✅
c.calamine - an ore of zinc ✅
d.cyolite - ❌ the ore is cryolite
✅ - is an ore
❌ - not an ore
Why is it important for scientists to use the scientific method?
A. Scientists would not ask questions if the scientific method were
not used.
B. Experiments would not produce any data without the scientific
method.
C. The scientific method helps scientists get accurate, repeatable
results,
D. Using the scientific method means that the results will support the
hypothesis
Explanation:
It provides an objective, standardized approach to conducting experiments and, in doing so, improves their results. By using a standardized approach in their investigations, scientists can feel confident that they will stick to the facts and limit the influence of personal, preconceived notions.
I hope this helps you out!
cuales son los nombres de la distribución de los electrones en un átomo ?
A container contains three gases. If the partial pressure of carbon dioxide is 0.50 atm, the partial pressure of nitrogen is 0.30 atm, and the partial pressure of methane is 0.40 atm, what’s the total pressure inside the container?
Answer:
1.20 atm
Explanation:
A container contains three gases. If the partial pressure of carbon dioxide is 0.50 atm, the partial pressure of nitrogen is 0.30 atm, and the partial pressure of methane is 0.40 atm, what’s the total pressure inside the container?
Do not let chemistry questions SCARE you! The TOTAL means
ADD THEM UP.
You can do this without a scientific calculator :-)
0.50 +0.30 + 0.40 = 1.20 atm
The organelle that serves as a microtubule organizing center during cell division is the
Answer:
Centríolo. Los Centríolos son orgánulos tubulares (en pares de dos en dos) que se encuentran en el citoplasma de las células animales, cerca de la membrana nuclear. Los centriolos tienen la función de organizar los microtúbulos, que son el sistema esquelético de la célula.
Explanation:
Espero te ayude
Which of the following pairs of elements could NOT react to form an ionic compound ? Check all that apply
Co and Br
C and O
K and F
Ag and O
Answer:
Ag and o
Explanation:
because they are not metals but not metals
i don't need to know why i just want the awnser
Answer:
I remember doing this in 7th,
1. D
2. B or D, more leaning on B though
3. A
how many valence electrons does P have?
Answer:
5 valence electrons
Explanation:
Phosphorus is in group VA so it has 5 valence electrons and Oxygen is in group VIA so each oxygen has 6 valence electrons.
Answer pls ASAPPP 50 pointsss!!
Answer:
There should only be one chemical reaction, this is because toasting the bread is not only using heat, but you cannot untoast the bread, and also theres a reaction with the amino acids and sugar in bread when it's cooked. I hope this helps you! :)
Answer:
One
Explanation:
One Chemical changes-It was when he toasted the bread. The heat changed the bread so that it has the crust on the outside