Answer:
Democritus first introduced the idea of the atom almost 2500 years ago.
Answer:
B. Democritus
Explanation:
12. Which formula shows a substance that is not molecular?
H₂
H2O
н
CO2
Answer:
the answer is H ..............
A liquid solvent is added to a flask containing an insoluble solid. The total volume of the solid and liquid together is 80.0 mL. The liquid solvent has a mass of 21.0 g and a density of 0.865 g/mL. Determine the mass of the solid given its density is 2.00 g/mL.
Answer:
111.44 g
Explanation:
We'll begin by calculating the volume of the solvent. This can be obtained as follow:
Mass of solvent = 21 g
Density of solvent = 0.865 g/mL.
Volume of solvent =?
Density = mass /volume
0.865 = 21 /volume of solvent
Cross multiply
0.865 × volume of solvent = 21
Divide both side by 0.865
Volume of solvent = 21 / 0.865
Volume of solvent = 24.28 mL
Next, we shall determine the volume of the solid. This can be obtained as follow:
Volume of solvent + solid = 80.0 mL.
Volume of solvent = 24.28 mL
Volume of solid =?
Volume of solid = (Volume of solvent + solid) – (Volume of solvent)
Volume of solid = 80 – 24.28
Volume of solid = 55.72 mL
Finally, we shall determine the mass of the solid. This can be obtained as follow:
Density of solid = 2.00 g/mL.
Volume of solid = 55.72 mL
Mass of solid =.?
Density = mass / volume
2 = mass of solid / 55.72
Cross multiply
Mass of solid = 2 × 55.72
Mass of solid = 111.44 g
Therefore, the mass of the solid is 111.44 g
Which of the following explains the high boiling
point of water?
a Surface tension
b Polarity
C Capillary action
d Hydrogen bonding
Answer:
The correct answer is - d. hydrogen bonding.
Explanation:
Water has strong hydrogen bonds between its molecules that require a very high amount of energy in order to break. Water molecules are joined together or bound with a strong intermolecular force called hydrogen bonds.
These bonds require more kinetic energy which means more temperature or heat in order to break the bonds and turn into steam and this is the reason it has a high boiling point.
True or false: this reaction is balanced.
2C2H6(g) + 70215)
True
4CO2(g) + 6H20(3)
False
Answer:
false
Explanation:
i did it
Disadvantages of modern periodic table?
Answer:
It has its elements with mass numbers phrased in many decimal places, it requires one to round off to get the actual value.
The atomic numbers of some elements such as Protonium were just guessed.
6. What is the total number of valence electrons in an
atom of germanium in the ground state?
Answer:
4⁺
Explanation:
Germanium (Ge) has an atomic number of 32 and belongs to group 14 on the periodic table. Germanium has an electronic configuration of [Ar] 3d¹⁰ 4s² 4p². There exist 32 electrons in its neutral atom. In fluorescent lights, germanium is utilized as a component of both alloys and phosphorus.
The electrons in the atom's outer shell are known as its valence electrons.
Thus, at the ground state, the outer shell of the Germanium atom has 4 electrons.
Reaction of 2,3-dimethyl-1-butene with HBr leads to an alkyl bromide, C6H13Br. On treatment of this alkyl bromide with KOH in methanol, elimination of HBr occurs and a hydrocarbon that is isomeric with the starting alkene is formed. What is the structure of this hydrocarbon, and how do you think it is formed from the alkyl bromide
Answer:
See explanation and image attached
Explanation:
The image attached shows the entire scheme of reactions mentioned in the question.
The first reaction is an addition reaction which yields a tertiary alkyl halide as shown in accordance with Markovnikov rule.
The second reaction is a dehydrohalogenation in which the base abstracts a proton from the alkyl halide followed by loss of a bromide ion to yield the corresponding alkene.
This alkene is an isomer of the starting material.
13. What does the Law of Conservation of Mass state?
Intramolecular forces of attraction are important in holding large molecules together.
a. True
b. False
Answer:
False. Intermolecular forces of attraction are important in holding large molecules together.
Explanation:
Within a molecule, atoms are held together by intramolecular forces. That is, intramolecular forces are the attractive forces that hold the atoms or ions that make up chemical substances (elements and compounds) together, forming a chemical bond.
On the other hand, intermolecular forces are those that act on different molecules or ions and that make them attract or repel each other. In other words, intermolecular forces are those that occur between the different molecules of a compound, and cause these molecules or ions to attract or repel each other.
So, intermolecular forces of attraction are important in holding large molecules together.
Avagadro’s number:
A: Is constant irrespective of mass of the gases
B: Varies according to the mass of the gases
C: Varies according to the pressure on the gases
D: All of the Above
Answer:
A: Is constant irrespective of mass of the gases
Explanation:
Avagadro's number, denoted by nA, is a number that represents the units in one mole of any substance. The number is 6.02214076 × 10²³ and the units can be atoms, molecules, ions, formula units etc.
That is;
1 mole of a substance = 6.022 × 10²³atoms, molecules, ions, electrons etc.
It is important to note that the Avagyadro's number is constant irrespective of mass of the gases that are involved.
what flora eat? pliz tell me someone
Answer:
flora eat food
Explanation:
because that what every living thing eats to grow.
Answer:
sugar??
Explanation:
plants photosynthesise to make their own food (mainly glucose) to be transported around the plant
rank in order the strongest to the weakest acid cbr3cooh, ch3cooh and ccl3cooh
Answer: Rank in order the strongest to the weakest acid is [tex]CCl_{3}COOH[/tex] > [tex]CBr_{3}COOH[/tex] > [tex]CH_{3}COOH[/tex].
Explanation:
More readily a substance is able to donate a hydrogen ion more will be its acidic strength. Hence, stronger will be the acid.
More is the electronegativity of atoms attached to the acid more easily it will donate a proton. Hence, more will be its acidic strength.
Chlorine is more electronegative in nature as compared to bromine. So,
[tex]CCl_{3}COOH[/tex] is more acidic than [tex]CBr_{3}COOH[/tex].
Since there is no electronegative group attached to [tex]CH_{3}COOH[/tex] so it is least acidic than [tex]CCl_{3}COOH[/tex] and [tex]CBr_{3}COOH[/tex].
Thus, we can conclude that rank in order the strongest to the weakest acid is [tex]CCl_{3}COOH[/tex] > [tex]CBr_{3}COOH[/tex] > [tex]CH_{3}COOH[/tex].
Determine the Concentration of the Unknown Strong Acid
In this activity you will use the virtual lab to determine the concentration of a strong monoprotic acid. To do this, you can perform
a titration using NaOH and phenolphthalein found in the virtual lab. (Note: The concentration of the acid is between 0.025M and
2.5M so you will need to dilute the NaOH solution so that the volume to reach the endpoint is between 10 and 50 mL).
Once you have determined the concentration of the acid, please enter your answer into a form at the bottom of this page.
Virtual
Lab
File -
Edit -
View
Help -
EN
Unknown Acid Problem
Stockroom
Workbench 1
Solutions
Glas
Tools
MacBook Pro
888
%
&
Difference between the hydrocarbons...Need help asap
Explanation:
Hydrocarbons are defined as organic compounds which are only made from carbon and hydrogen atoms.
There are mainly 3 types of hydrocarbons:
Alkanes are the type of hydrocarbons where a single bond is present between the carbon atoms. The general formula for these is [tex]C_nH_{2n+2}[/tex], where 'n' is the number of carbon atoms.Alkenes are the type of hydrocarbons where at least one double bond is present between the carbon atoms. The general formula for these is [tex]C_nH_{2n}[/tex], where 'n' is the number of carbon atoms.Alkynes are the type of hydrocarbons where at least one triple bond is present between the carbon atoms. The general formula for these is [tex]C_nH_{2n-2}, where 'n' is the number of carbon atoms.What is the noble gas electron configuration of bismuth (Bi)?
Answer:
The chemical symbol for Bismuth is Bi. Electron Configuration and Oxidation States of Bismuth. Electron configuration of Bismuth is [Hg] 6p3. Possible oxidation states are +3,5.
Guys i need a long inforation about....
"Formation of colloids"
Please and thank you
Answer:
Colloids
There are two basic methods of forming a colloid: reduction of larger particles to colloidal size, and condensation of smaller particles (e.g., molecules) into colloidal particles. Some substances (e.g., gelatin or glue) are easily dispersed (in the proper solvent) to form a colloid; this spontaneous dispersion is called peptization. A metal can be dispersed by evaporating it in an electric arc; if the electrodes are immersed in water, colloidal particles of the metal form as the metal vapor cools. A solid (e.g., paint pigment) can be reduced to colloidal particles in a colloid mill, a mechanical device that uses a shearing force to break apart the larger particles. An emulsion is often prepared by homogenization, usually with the addition of an emulsifying agent. The above methods involve breaking down a larger substance into colloidal particles. Condensation of smaller particles to form a colloid usually involves chemical reactions—typically displacement, hydrolysis, or oxidation and reduction.
The student adds 0.0010 mol of NaOH(s) to solution Y, and adds 0.0010 mol of NaOH(s) to solution Z. Assume that the volume of each solution does not change when the NaOH(s) is added. The pH of solution Y changes much more than the pH of solution Z changes. Explain this observation.
Answer:
The answer is in the explanation.
Explanation:
A buffer is defined as the aqueous mixture of a weak acid and its conjugate base or vice versa. Buffers are able to avoid the pH change of a solution when strong acid or bases are added (As NaOH).
Based on the experiment, it is possible that the solution Z was a buffer and Y another kind of solution. For this reson, pH of the solution Y changes much more than the pH of solution Z changes despite the amount of NaOH added is the same in both solutions.
someone answer please
Answer:
A
Explanation:
Arrange the following molecules in order of decreasing polarity of their bonds.
a. PBr3
b. SF2
c. H2O
d. NCl3
Answer:
SF2 > H2O > PBr3 > NCl3
Explanation:
Compare the electronegativity values for the atoms and classify the nature of the bonding based on the electronegativity difference.
P has an electronegativity of 2.1, while Br has an electronegativity of 2.96. The difference is 0.86, indicating that these atoms will form covalent bonds.
S has an electronegativity of 2.58 while F has an electronegativity of 4.0. The difference is 1.42, indicating that these atoms will form polar covalent bonds.
O has an electronegativity of 3.5 while H has an electronegativity of 2.1. The difference is 1.4, indicating that these atoms will form polar covalent bonds.
N has an electronegativity of 3.04, whereas Cl has an electronegativity of 3.5. This difference of 0.46 indicates that these atoms will form covalent bonds.
We know that the greater the electronegativity, the higher the polarity. In decreasing order of polarity, we have:
SF2 > H2O > PBr3 > NCl3
Of course, most of us know the reaction between Coca Cola and Mentos. So please can someone provide a chemical equation which contains the ingredients in Coca Cola and Mentos that will make it to foam?
Answer:
As the Mentos candy sinks in the bottle, the candy causes the production of more and more carbon dioxide bubbles, and the rising bubbles react with carbon dioxide that is still dissolved in the soda to cause more carbon dioxide to be freed and create even more bubbles, resulting in the eruption
help!! An atomic number of 4, an atomic mass of 8 and a charge of +1.
Answer:
berylium
Explanation:
atomic number 4 atomic mass 8 and charge +1
The average molecular speed in a sample of Ar gas at a certain temperature is 213 m/s. The average molecular speed in a sample of Ne gas is ______ m/s at the same temperature.
Answer:
300m/s is the average molecular speed of Ne
Explanation:
Based on Graham's law, the ratio of speed of two gases under constant temperature is equal to the square root of the inverse of their molar masses. The equation is:
v1 / v2 = √m2 / √m1
Where v is the speed of the gas and m the molar mass of the gas
Assuming gas 1 is Argon and gas 2 is Neon:
v1 = 213m/s
v2 = ?
m2 = 20.18g/mol
m1 = 39.948g/mol
213m/s / v2 = √20.18g/mol / √39.948g/mol
v2 = 213m/s / 0.71074
v2 = 300m/s is the average molecular speed of Ne
QUESTION 3 (a) Ammonium sulphate, (NH),50, is a soluble salt and it is used in agriculture as fertiliser. 5 g of ammonium sulphate is dissolved in 1 litre of water to produce ammonium sulphate solution. (Relative atomie mass: H = 1, N = 14,0 = 16, )
Calculate
(1) the number of inoles of dissolved ammonium sulphate
(ii) the number of molecules present in the ammonium sulphate solution.
(iii) the number of positive ions present in the ammonium sulphate solution
(iv) the number of negative ions present in the ammonium sulphate solution
(v) the total number of ions present in the ammonium sulphate solution
Answer:
The equation: (NH₄)₂SO₄ = 2NH4(+) + SO4(-2)
The number of moles = 5 g / 132.14 g/mol = 0.038 mol
The number of molecules = 0.038 X 6.022x10^23 = 2.29x10^23
the number of positive ions present in the ammonium sulphate solution:
2 positive ions for every 1 molecule of (NH₄)₂SO₄
so 2 x 2.29x10^23 = 4.58x10^23
the number of negative ions present in the ammonium sulphate solution
1 negative ion for every 1 molecule of (NH₄)₂SO₄
so 1 x 2.29x10^23 = 2.29x10^23
the total number of ions present in the ammonium sulphate solution
4.58x10^23 + 2.29x10^23 = 6.87x10^23
Common decay process definition in your own words
Answer:
Your welcome! :)
Explanation:
THE PROCESS IS: Radioactive decay involves the emission of a particle and/or energy as one atom changes into another. In most instances, the atom changes its identity to become a new element.
THE DEFINITION IS: Decay, decompose, rot, putrefy, spoil mean to undergo destructive dissolution. decay implies a slow change from a state of soundness or perfection. a decaying mansion decompose stresses a breaking down by chemical change and when applied to organic matter a corruption.
(a) Describe the process by which Nitrogen is obtained from air on a large scale
The element nitrogen exists as a gas and is obtained from air on a large scale by fractional distillation of air.
What is an element?An element is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
Learn more about element,here:
https://brainly.com/question/14347616
#SPJ2
In what form is energy that is NOT used for life processes released from living things?
1. Thermal energy
2. Chemical energy
3. Light energy
4. Sound energy
Answer:
Correct answer would be Option 2, Chemical Energy
Hope this helps!
Waves are generated when energy passes through causing them to move matter through ____ ?
Answer:
sending heat waves and vibrations
The reaction of bromine gas with chlorine gas, shown here, has a Keq value of 7.20 at 200°C. If a closed vessel was charged with the two reactants, each at an initial concentration of 0.200 M, but with no initial concentration of BrCl, what would be the equilibrium concentration of Br2, Cl2 and BrCl(g)?
Br2(g) + Cl2(g) ↔ 2BrCl(g) K = 7.20
Answer:
[tex][Cl_2]=[Br_2]=0.856M[/tex]
[tex][BrCl]=0.229M[/tex]
Explanation:
Hello there!
In this case, for this chemical equilibrium problem, it turns out possible for us to solve for the equilibrium concentrations by firstly setting up the equilibrium expression:
[tex]Keq=\frac{[BrCl]^2}{[Cl_2][Br_2]}[/tex]
Thus, by plugging in an ICE chart, in terms of x (reaction extent), we can write:
[tex]7.20=\frac{(2x)^2}{(0.200-x)^2}[/tex]
And could be solved for x as follows:
[tex]\sqrt{7.20} =\sqrt{\frac{(2x)^2}{(0.200-x)^2} } \\\\2.68=\frac{2x}{0.200-x} \\\\x=0.1146M[/tex]
Therefore, the equilibrium concentrations turn out to be:
[tex][Cl_2]=[Br_2]=0.200M-0.1146M=0.856M[/tex]
[tex][BrCl]=2*0.1146M=0.229M[/tex]
Regards!
The citric acid cycle has a catabolic role, oxidizing acetate into CO2 and generating energy, and an anabolic role.
a. True
b. False
1 point
What is the correct balanced equation for the double displacement
reaction provided?
CaBr2+2NaOH???
a) CaBr2+2NaOH
>CaNa
+ BrOH
b) CaBr2
+ NaOH → Ca(OH)2
+NaBr
c) CaBr2 NaOH> CaBr2
+NaOH
d)CaBr2
+ 2NaOH
→ Ca(OH)2
+2NaBr
Option A
Option B
Option C
Option D
Answer:
Option D
Explanation:
A double displacement reaction is a type of reaction in which two reactants exchange ions to form two new compounds.
CaBr2 + 2NaOH → Ca(OH)2 + 2NaBr
Calcium Bromide + Sodium Hydroxide = Portlandite + Sodium Bromide
