a compound is a pure substance made up of two or more elements chemically combined a molecule is defined as the smallest particle of an element which can exist separately elements are pure substances which can not be split into simple substances by chemical means the atom is defined as the smallest particle of an element which can take part in a chemical change so I think the difference between the molecule of a compound is bigger than the molecule of a compound
Using dobereiner's triads, what conclusion could have been made about magnesium
Answer:
Triads were groups of 3 elements with similar chemical and physical properties. Beryllium, magnesium, and calcium are all earth alkalis found in the earth
Explanation:
in which instrument of the following the washer works works as a valve? a)syringe b)hydraulic garage lift c)air pump d)watre pump
Answer:
A
Explanation:
The instrument in which the washer works as a valve is A ; syringe
Each instrument listed have a washer and a valve, but of all the instruments listed above the instrument that its washer works also as a valve is the syringe.
A syringe is composed of a thin tube and a thinner hollow needle attached to the end of the thin tube. the needle is used and take in liquids and also expel liquids from the syringe ( i.e. washer and valve )
hence the instrument that its washer also functions as a valve is the syringe.
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Plz Help I have One more time To retake and I can't fail it..
Answer:
A
Explanation:
Hydrogen bonds are intermolecular forces of interaction that exist between molecules of a substance in which hydrogen is bonded to a highly electronegative atom. Hydrogen bonds are strong intermolecular forces and account for high melting and boiling points of small molecules such as water. They stem from dipole-dipole interaction between molecules of a substance.
Metallic bonds are bond forces which exist in a metal. Metal cations are held together by a sea of electrons via electrostatic interaction.
The ionic bond is formed by transfer of electrons from one atom to another leading to the formation of an ion pair held together by electrostatic attraction.
Metallic bonds and hydrogen bonds are much weaker than ionic bonds. Ionic compounds are known to have high melting and boiling points.
Question 6 I need help
The answer is zero also I suggest googling the questions there is a quizlet with the answers
Putting rock salt on the roads during a snowstorm is an example of: A. Boiling point elevation B. Vapor pressure raising C. Vapor pressure lowering D. Freezing point depression
Answer:
The correct answer is - D. Freezing point depression.
Explanation:
When rock salt is spread over snow-covered icy roads, it generates a liquid layer over it by melting from the surface thereby lowering or depression in the freezing point below the ice.
Therefore, due to this liquid layer comes into the contact with the ice present on the road and causes other ice to melts. This keeps on decreasing the volume of the ice on the road therefore, rock salts spread on the roads during a snowstorm.
Analysis of an ore of calcium shows that it contains 13.61 g calcium and 21.77 g oxygen in a 46.28-g sample. Calculate the percent composition of this compound.
Answer:
29.41% of Calcium and 47.04% of Oxygen
Explanation:
The percent composition of an atom in a molecule is defined as 100 times the ratio between the mass of the atom and the mass of the molecule.
The mass of the molecule of the problem (Ore) is 46.28g. That means the percent composition of Calcium is:
13.61g / 46.28g * 100 = 29.41% of Calcium
And percent composition of Oxygen is:
21.77g / 46.28g * 100 = 47.04% of Oxygen
Which of the following statements about periodic trends is true?
O both electronegativity and atomic radius decrease from bottom to top and from left to right on
the periodic table.
O both electronegativity and ionization energy increase from bottom to top and from left to right
on the periodic table.
O both atomic radius and ionization energy increase from bottom to top and from right to left on
the periodic table.
O electronegativity, ionization energy and atomic radius all decrease from bottom to top and from
left to right on the periodic table.
both electronegativity and ionization energy increase from bottom to top and from left to right
on the periodic table.
What is the change in enthalpy of the first reaction below, given the enthalpies of the other two reactions?
Here's the reactions:
There was a formatting issue with the specific chemistry symbols, there all correct in the picture below
2C(s) + O2(g) → 2CO(g)
C(s) + O2(g) → CO2(g) ∆H0= -394 KJ/mol
CO(s) + 1/2 O2(g) → CO2(g) ∆H0= -283 KJ/mol
There was a formatting issue with the specific chemistry symbols, there all correct in the picture below
Answer:
∆H0 = -222kJ/mol
Explanation:
Using Hess's law, we can find the ΔH of a reaction from the sum of another related reactions as follows:
Using the reactions:
(1) C(s) + O2(g) → CO2(g) ∆H0= -394 KJ/mol
(2) CO(s) + 1/2 O2(g) → CO2(g) ∆H0= -283 KJ/mol
Twice (1):
2C(s) + 2O2(g) → 2CO2(g) ∆H0= 2*-394 KJ/mol = -788kJ/mol
The inverse reaction of (2):
-(2) CO2(g) → CO(g) + 1/2 O2(g) ∆H0= 283 KJ/mol
Twice this reaction:
2*-(2) 2CO2(g) → 2CO(s) + O2(g) ∆H0= 2*283 KJ/mol= 566kJ/mol
Now, the sum of 2*(1) - 2*(2) produce:
2C(s) + 2O2(g) + 2CO2(g)→ 2CO2(g) + 2CO(g) + O2(g) ∆H0= -788kJ/mol + 566kJ/mol
Subtracting the molecules that ar in both sides of the reaction:
2C(s) + O2(g) → 2CO(g) ∆H0 = -222kJ/mol
what does high pressure systems usually cause?
how many Molecules and atoms of the product 2H2O+ O2
Answer:
A water molecule is composed of two hydrogen atom and one oxygen atom but you can't simply take two hydrogen atom stick them onto an oxygen atom
A gas that was cooled to 200 Kelvin has a volume of 65.8 L. If its initial volume was 132.4 L, what was its initial temperature?
Answer:
Initial temperature, T1 = 99.4 Kelvin
Explanation:
Given the following data;
Initial volume, V1 = 65.8 LitresFinal temperature, T2 = 200 KelvinFinal volume, V2 = 132.4 LitresTo find the initial temperature (T1), we would use Charles' law;
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles' law is given by the formula;
[tex] \frac {V}{T} = K [/tex]
[tex] \frac {V_{1}}{T_{1}} = \frac {V_{2}}{T_{2}} [/tex]
Making T1 as the subject formula, we have;
[tex] T_{1} = \frac {V_{1}T_{2}}{V_{2}} [/tex]
Substituting the values into the formula, we have;
[tex] T_{1} = \frac {65.8 * 200}{132.4} [/tex]
[tex] T_{1} = \frac {13160}{132.4} [/tex]
Initial temperature, T1 = 99.4 Kelvin
Ethylene glycol (antifreeze) has a density of 1.11 g/cm^3. What is the volume (in m^3) of 9.7 tons?(1 ton = 2.000*10^3lb; 1 kg= 2.2046 lb
Answer: The volume of 9.7 tons of given ethylene glycol is 0.0079 [tex]m^{3}[/tex].
Explanation:
Given: Density = 1.11 [tex]g/cm^{3}[/tex]
Mass = 9.7 tons
Convert tons into lb as follows.
[tex]1 ton = 2 \times 10^{3} lb\\9.7 ton = 9.7 ton \times 2 \times 10^{3} \frac{lb}{1 ton}\\= 19.4 \times 10^{3} lb[/tex]
Now, lb is converted into kg as follows.
[tex]1 kg = 2.2046 lb\\1 lb = 0.453592 kg\\19.4 \times 10^{3} lb = 19.4 \times 10^{3} lb \times 0.453592 \frac{kg}{1 lb}\\= 8.79 kg[/tex]
1 kg = 1000 g
So, 8.79 kg = 8790 g
Density is the mass of a substance divided by its volume. Hence, volume of ethylene glycol is calculated as follows.
[tex]Density = \frac{mass}{volume}\\1.11 g/cm^{3} = \frac{8790 g}{volume}\\volume = 7918.92 cm^{3} (1 cm^{3} = 10^{-6} m^{3})\\= 0.0079 m^{3}[/tex]
Thus, we can conclude that the volume of 9.7 tons of given ethylene glycol is 0.0079 [tex]m^{3}[/tex].
can u plz solve it n send the answer
1. Cl2 + H2O → HOCl + HCl
2. Tooth decay starts when when the pH of the mouth is lower than 5.5. Tooth enamel is made up of calcium phosphate and it is one of the hardest substances of the body. But it is corroded when the pH is less than 5.5. The bacteria of our mouth produce acids by degradation of sugar and food particles remaining in our mouth after eating food.
3. Fluorine salts are added in toothpaste to protect our teeth from tooth decay. Fluorine salts are mildly basic, so they neutrelise the acid in our mouth that leads to tooth decay.
4. Tincture of iodine is iodine, pottasium iodide and sodium iodide dissolved in ethanol. Iodine acts in an antiseptic manner by destroying microbial proteins and DNA.
5. Tincture of iodine is clear and reddish brown liquid.
The air you breathe is a solution of about 78% nitrogen and 21% oxygen and 1% other
gases. Which substance is the solvent? Explain how you know
Answer:
I believe nitrogen would act as the solvent, I know this because there is a higher percentage of it than oxygen and other.
In the air composition provided, nitrogen is the solvent, while oxygen and the other gases are the solutes dissolved within the nitrogen solvent.
In a solution, the solute is the substance that is present in a smaller quantity and is dissolved in a larger quantity of another substance called the solvent. The solute may dissolve in the solvent to create a homogeneous mixture.
In the given case, air is a mixture of gases, and the major components are nitrogen (78%) and oxygen (21%), with a small percentage of other gases (1%). Here, nitrogen and oxygen are the solutes, and the remaining gases are also solutes, but in a smaller proportion.
The solvent is the component that dissolves the solute, and in the case of air, nitrogen is acting as the solvent. Nitrogen, being the most abundant gas in the mixture, forms the "base" or "carrier" for the other gases to be mixed within. Oxygen and the other gases dissolve or mix into nitrogen gas, creating a homogeneous mixture that we breathe.
Thus, in the air composition provided, nitrogen is the solvent, while oxygen and the other gases are the solutes dissolved within the nitrogen solvent.
Learn more about the solvents here:
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how do i calculate the concentration of a certain solution
Answer:
Divide the mass of the solute by the total volume of the solution. Write out the equation C = m/V, where m is the mass of the solute and V is the total volume of the solution. Plug in the values you found for the mass and volume, and divide them to find the concentration of your solution.
Mole concept
Calculate the number of iodine atoms in 4.50g of iodine gas
Answer:
0.017g/mol
Explanation:
according to the mole concept to calculate the number of moles of a substance you use the formula
number of moles= mass/molecular mass
=4.5g/254g/mole
=0.017moles
I hope this helps and sorry if it's wrong
Values for the molar mass of hydrogen, oxygen, and water molecules are
given in the table below. What mass of water is formed when 2 moles of
hydrogen react with 1 mole of oxygen to form water?
Molecule
Molar mass (g/mol)
H2
2.02
02
32.00
H20
18.01
A.9.00 g
B. 36.02 g
C. 2.00 g
D. 18.01 g
Answer:
36.02g bbbbbbbbbbb hbbnjkkkj
Answer:
36.02g
Explanation:
Hope this helps!
When a vacancy exists in an inner electron shell of an atom (as a result of photoelectric effect, Compton scattering, or bombardment by other electrons), the energy liberated when this vacancy is filled, instead of emerging from the atom as fluorescent radiation, can be transferred to another electron of the atom, thereby ejecting the electron. Such an emitted electron is called a(n) _____ electron
Answer:
The answer is "Auger".
Explanation:
The Auger effect is an effect size when the vacancy of even an atom throughout the inner shell was complemented by the release of even an electron from the same atom. Whenever a central electron is lost, a higher energy level electron can drop into the void and release energy, which can be the result.
Look at the two thermometers. Which statement explains which thermometer is more appropriate to measure the temperature of a liquid at 43.6 C
Answer:
I don't know
Explanation: Where are the statements?
Iupac name for this?
Answer:
Explanation:
4,5 diethyl-2 fluoro-3-methylheptanal
What was the main aim of Cavendish’s work?
Answer:
The Cavendish experiment, performed in 1797–1798 by English scientist Henry Cavendish, was the first experiment to measure the force of gravity between masses in the laboratory and the first to yield accurate values for the gravitational constant
Explanation:
I think that's correct
Which is the formula mass of (NH4)2SO4?
96.07 amu
114.12 amu
116.17 amu
132.17 amu
Answer:
132.17amu
Explanation:
(14.01+1.01 multiplied by 4)=18.05×2=36.1
36.1+32.07= 68.17
16.00×4=64
68.17+64=132.17
Answer:
132.17 amu
Explanation:
just took the test. got 100
2.5 kilogram into gram
Answer:
2500grams
hope this helps
Answer: 2500 gram
Explanation:
Concept:
Here, we need to know the idea of unit conversion.
Unit conversion is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.
1 kg = 1000 g
Solve:
1kg = 1000g
2.5kg = 2.5 × 1000 = 2500g
Hope this helps!! :)
Please let me know if you have any questions
How do the substances compare?
Name five metal which are both dilute and memorable? class 10
Some consumers, like lions, do not eat plants or any other producers. They only eat other animals. How do lions obtain the carbon they need?
whoever gets it first gets to be Brainlist
Answer:
BHAI SECOND OPTION HOGA
Answer:b
Explanation:
Please hurry this is due tomorrow morning
A student is studying the ways different elements are similar to one another. Diagrams of
atoms from four different elements are shown below.
Which two atoms are of elements in the same group in the periodic table?
F Atom 1 and Atom 2
G Atom 1 and Atom 4
H Atom 2 and Atom 3
J Atom 3 and Atom 4
Given: CNO2
a) Draw the Lewis structures (Do not forget to show the calculation of the number of available valance electrons)
b) Name the geometry shape
c) Indicate the polarity (polar or non-polar)
Answer:
since there are no lone pairs on the central atom, this would be a trigonal planar molecule. It's polar because the shape of it does not cancel its polarity (you can think of it as not having a balanced electronegativity pull, since the nitrogen is pulling on one side, and the oxygens are pulling on the other. It would be nonpolar if the there were 3 Oxygens).
Sorry this take a little bit long. I was a little confused by the odd valence number
calculate the mass of magnesium needed to make 25g of magnesium oxide
mark brainliest of correct xx
Answer:
15g
Explanation:
First, you need to correct the answer to the previous question. The percentage by mass of Mg in MgO =
Mg = 24.3 amu
O = 16.0 amu
The total mass of MgO = 40.3 amu
To calculate the percent composition of Mg:
% = 24.3/40.3 x 100
% = 60
To calculate the mass of Mg needed to make 25g of MgO:
x/25g = 60%/100%
100x = (25)(60)
100x = 1500
x = 15g
A science student observes that a dissolvable antacid tablet acts faster in relieving stomach pain when taken with warm water than when taken with water at room temperature. Based on the observation, suggest a potential problem that can be studied. Also, list the dependent, independent, and controlled variables that can exist in such an investigation.
Answer:
We know that an antacid is a base that can neutralize the stomach acid when ingested. The student observed that a soluble antacid tablet reacted faster in relieving pain due to the excess acid secreted in the stomach. So, the problem that can be studied is the effect of temperature on the rate of neutralization of stomach acid by the antacid. The independent variable is the one the student is going to vary that is the temperature. The dependent variable is the rate of reaction or the time taken for an antacid tablet to neutralize the acid present in stomach. The controlled variable is the tablet taken, that is the student should use a specific antacid tablet to ensure that the rate of reaction or the time taken for the antacid tablet to neutralize the acid present in stomach is not affected by the chemical composition of tablet.
Explanation:
Hope u understood.
