what is metal's I need answer
Answer:
objects thaty release 0H+ and H- ions when dissociated
Explanation:
in chemistry
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Why do we feel cold when we touch the iron?
A) Heat flows from iron to our body.
B) Heat flows from our body to iron.
C) Heat flows from iron to iron
D) Heat does not not flow
Please answer it soon as possible
Heat flows from our body to iron
Which line of evidence has been traditionally accepted as conclusive proof of evolution? the presumed age of the Earth the fossil record Darwin's treatise on the Origin of the Species absolute dating of rocks
The most generally accepted form of conclusive evidence for the theory of Evolution is the fossil record.
What is the theory of Evolution?The theory of evolution was proposed by Charles Darwin.It states that as time passes, organisms evolve to better adapt to their environments.This is closely related to natural selection, which is considered a driving force of evolution. How the fossil record supports this theoryThe fossil record provides essential data to support this claim.The data comes in the form of the comparison between fossils of two closely related organisms, separated by a matter of generations, that present changes in the genetic code that made them more apt for survival.Therefore, we can confirm that the most generally accepted form of conclusive evidence for evolution is the presence of fossils that show the genetic correlation between two organisms and the progression of evolution between them.
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Need ASAP will give brainlist
Answer:
i think the answer will be C.
Explanation:
correct me if im wrong
loveya
The density of crystalline cl2 at 160K is 2.02g/cm3. calculate the molar volumes
The molar volume (Vm) is the volume occupied by one mole of a chemical element or chemical compound at standard temperature and pressure (STP). The molar volume of Cl₂ is 35.10 cm³/mol.
One mole of any gas has a defined volume when it is at a particular temperature and pressure. The relationship between molar mass and molar volume is direct and inverse, respectively.
Two gases have equal molecules if their volumes are the same at a given temperature and pressure. A gas's volume is directly proportional to the number of moles it contains. One mole of any gas takes up 22.4 L of space at STP.
The expression used to calculate molar volume is:
Molar volume = Molar mass / Density
The molar mass of Cl₂ = 70.906 g/mol
Molar volume = 70.906 / 2.02
Molar volume = 35.10 cm³/mol
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whats a covalent bond ?
Answer:
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
Answer:
A covalent bond is the “interatomic linkage that results from the sharing of an electron pair between two atoms.”
Explanation:
Hope this helps have a nice day
1. In a heterogeneous mixture, the substances
A. can be physically separated.
B. are chemically combined.
C. can only be separated through chemical
processes.
D. break down into new substances.
Please answer
What is the pH when 30.0 ml of 0.005 M HF is mixed with 15.0 ml of 0.01 M NaOH?
Answer:
7.36
Explanation:
my teacher said that was the right answer
why lysine is less basic than arginine
Answer:
Arginine is the most basic among them because it contains guanidine side group, −(CH2)4NHC(=NH)NH2, which is basic. Lysine has two amine groups, which makes it overall basic because of the second isolated amine group (−(CH2)4NH2). Histidine, on the other hand, contains imidazole group, which is also basic.
Explanation:
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if its helps please please please please please please please reply
what is the approximate pH of a solution labeled 0.050 M HCLO ?
Answer:
It would be around 4.4 in PH
Explanation:
I hope this helped.
What is the most soluble in water? iconic, covalent, metallic or nonmetallic
write the conjugate bases of the following acids ? H₂S , HCOOH ,HSO₃¯ , HSO¯₄ , HS¯, HNO₂ ,HCN,?
Answer:
HS(-)
HCOO(-)
SO3(2-)
SO4(2-)
S(2-)
NO2(-)
CN(-)
Explanation:
The parenthesis are the charges of the compounds. When an acid is introduced in a base, it dissociates its Hydrogens giving protons to the base. In this case, if you remove one hydrogen of a compound, you will reduce the charge of a compound since basically you're removing a positive charge from a compound. If you need to, I can explain how the thing of the charges work.
In fact, the definition of a conjugate base is a compound created when the original (an acid) compound dissacioate an atom of hydrogen (a proton) in a base.
Which of these is a characteristic of warm air?
It transfers energy through radiation.
Its molecules are far apart.
It sinks due to convection.
It cools the land below it.
Answer: B.
Explanation:
Warm air molecules are far apart, while cool air molecules are packed closer together.
Answer: A It Transfers energy through radiation
Explanation: I jut got done with the exam 15 min ago
Select True or False: The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol. Bloom's Level: Understand
True, the entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.
The third law of thermodynamics states that, the entropy of a system approaches a constant value as the temperature of the system approaches absolute zero.
The entropy of any perfectly ordered, crystalline substance at absolute zero temperature is zero. That is, the entropy of a pure, perfect crystalline substance at 0 K is 0 J/K.
Thus, we can conclude that the given statement is true. The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.
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how are homogeneous mixtures different from heterogeneous mixtures
Answer:
In Homogenous mixtures, the whole mixture is in the same phase whereas in Heterogeneous mixture, substances can be of two phases and layers may separate. ... Homogeneous mixture could be exemplified as a sugar solution or salt solution whereas Mixture of salt and sand could be used as an example of Heterogeneous mixture.
Some insects, such as water striders, are able to walk on water. In one or two sentences, make and justify a conjecture about a property of water that would allow the insect to walk on it.(2 points) SHORT ANSWER
Insects can walk on water due to its surface tension, which is something like 0.07 J/m^2.
So water (and most liquids) have a property called surface tension, which is defined as the amount of energy that you need to increase the surface per area unit of the liquid volume.
Thus, if the insect has smaller energy than that, it would not change the surface of the liquid, allowing it to walk on the water's surface.
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Answer: They are able to walk on water because of surface tension. Liquid molecules are held together by electrostatic forces. Molecules on the surface of the water are attracted to surrounding molecules and tension is created as the molecules get pulled down. This allows them to distribute their body weight over the water’s surface without breaking through that force.
Explanation:
Gaseous methane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water. If 0.809g of carbon dioxide is produced from the reaction of 0.80g of methane and 2.1g of oxygen gas, calculate the percent yield of carbon dioxide.
Be sure your answer has the correct number of significant digits in it.
Answer:
About 58%.
Explanation:
We first need to write the balanced chemical equation:
[tex]\displaystyle \text{CH$_4$(g)} + 2\text{O$_2$(g)} \longrightarrow \text{CO$_2$(g)} + 2\text{H$_2$O(g)}[/tex]
We are given that 0.809 g of carbon dioxide was produced from the reaction of 0.80 g of methane and 2.1 g of oxygen gas. We want to calculate the percent yield of carbon dioxide.
First, determine the limiting reagent. We can convert each initial mass to the mass of carbon dioxide using stoichiometry. The molar mass of methane is 16.05 g/mol and the molar mass of carbon dioxie is 44.01 g/mol. From the equation, every one mole of carbon dioxide is produced from every one mole of methane and every two moles of oxygen gas.
0.80 g of methane will (theoretically) produce:
[tex]\displaystyle \begin{aligned} 0.80 \text{ g CH$_4$} &\cdot \frac{1 \text{ mol CH$_4$}}{16.05 \text{ g CH$_4$}} \cdot \frac{1 \text{ mol CO$_2$}}{1 \text{ mol CH$_4$}} \cdot \frac{44.01 \text{ g CO$_2$}}{1 \text{ mol CO$_2$}} \\ \\ & = 2.2 \text{ g CO$_2$}\end{aligned}[/tex]
2.1 g of oxygen gas will (theoretically) produce:
[tex]\displaystyle \begin{aligned} 2.1 \text{ g O$_2$} & \cdot \frac{ 1 \text{ mol O$_2$}}{32.00 \text{ g O$_2$}} \cdot \frac{1 \text{ mol CO$_2$}}{2 \text{ mol O$_2$}}\cdot \frac{44.01 \text{ g CO$_2$}}{1 \text{ mol CO$_2$}} \\ \\ & = 1.4 \text{ g CO$_2$} \end{aligned}[/tex]
Hence, oxygen gas is the limiting reagent. A maximum of 1.4 g of carbon dioxide can be produced.
To calculate the percent yield, we divide the actual yield by the theoretical yield. The actual yield was 0.809 g and the theoretical yield is 1.4 g. Hence:
[tex]\displaystyle \begin{aligned} \%\text{Yield} & = \frac{\text{Actual}}{\text{Theoretical}} \times 100\% \\ \\ & = \frac{(0.809\text{ g CO$_2$})}{(1.4\text{ g CO$_2$})} \times 100\% \\ \\ & = 58\%\end{aligned}[/tex]
In conclusion, the percent yield of carbon dioxide is about 58%.
what percentage of oxygen is attributed fossil fuel combustion
A.43%
B.77%
C.4%
D.17%
Answer:
C. 4%
Explanation:
The answer is 4%
what is the result of collisions of particles with an object? *
A. pressure on the object
B. pressure away from the object
C. the object gets lighter
D. the object gets heavier
Answer:
Particle collisions cause pressure.
Explanation:
The fast motion of gas particles gives them a relatively large amount of kinetic energy. Recall that kinetic energy is the energy that an object possesses because of its motion. The particles of a gas move in straight-line motion until they collide with another particle or with one of the walls of its container.
. What is meant by periodic in Periodic Table?
a. the table has b. the elements
repeated cycles occur more than
once
c. the table is only d. the table can be
good for so long changed as
needed
Answer:
B
Explanation:
Periodic refers to properties that repeat at certain intervals. Click to see full answer. In respect to this, what does periodic mean in the term periodic table? In the context of chemistry and the periodic table, periodicity refers to trends or recurring variations in element properties with increasing atomic number.
How many teaspoons are equal to 1 mole of water if there is 0.23 teaspoon for every 1 g?
A. 0.46 teaspoon
B. 3.68 teaspoons
C. 4.14 teaspoons
D. 18 teaspoons
Answer:it's b hope that help
The molar mass of water is 18 g. Given that there are 0.23 teaspoon for every 1 g. Thus , for 18 g there would be 4.14 teaspoons.
What is one mole?Any substance that contains 6.022 × 10²³ number of atoms is called one mole of that substance. The mass of a compound or molecule containing these much atoms is called its molar mass.
Molar mass of water is 18 g. Thus, it means that one mole of water weighs 18 g. Given that for every 1 g of water there are 0.23 teaspoon. Thus, number of teaspoons for one mole or 18 g of water is:
number of teaspoons = 18 g × 0.23 /1 g
= 4.14 teaspoons.
Therefore, 4.14 teaspoons are required for one mole of water.
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define conjugate Base and conjugate acid
Explanation:
conjugated base is substance formed when an acid loses
a hydrogen ion.
conjugated acid is a type of acid that is formed when a base accepts a proton in solution
PLEASE HELP ME!!
The molar mass of BF3 is 67.81 g/mol. How many molecules of BF3 are there in 2 g? (1 point)
A) 1.776 x 1022
B) 8.881 x 1021
C) 1.204 x 1024
D) 4.084 x 1025
Answer:
A
Explanation:
We are given that the molar mass of boron triflouride BF₃ is 67.81 g/mol. We want to determine the number of molecules of BF₃ in 2 g of BF₃.
Recall that there are 6.02 × 10²³ molecules in any mole of a substance. In other words, there are 6.02 × 10²³ BF₃ molecules in a mole of BF₃. Starting with the initial value, multiply:
[tex]\displaystyle \begin{aligned} 2\text{ g BF$_3$}&\cdot \frac{1\text{ mol BF$_3$}}{67.81 \text{ g BF$_3$}} \cdot \frac{6.02\times 10^{23} \text{ molecules BF$_3$}}{1 \text{ mol BF$_3$}} \\ \\ &= 1.776 \times 10^{22} \text{ molecules BF$_3$}\end{aligned}[/tex]
Hence, our answer is A.
*Perhaps it rendered the values incorrectly, but since we started with only 2 g of BF₃, our resulting calculation should only contain one significant digit. Hence, the correct answer should be 2 × 10²² molecules of BF₃.
The molecules of BF₃ that are there in 2 g is 1.776 × 10²² molecules and the correct option is option A.
The mole is an amount unit similar to familiar units like pair, dozen, gross, etc. It provides a specific measure of the number of atoms or molecules in a bulk sample of matter.
A mole is defined as the amount of substance containing the same number of atoms, molecules, ions, etc. as the number of atoms in a sample of pure 12C weighing exactly 12 g.
Given,
Molar mass of BF₃ = 67.81 g/mol
Mass = 2g
Moles = mass / molar mass
= 2 / 67.81
= 0.029 moles
1 mole = 6.023 × 10²³
0.029 moles = 6.023 × 10²³ × 0.029
= 1.776 × 10²² molecules
Thus, the ideal selection is option A.
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How does the water cycle contribute to the "brown ocean" effect?
Answer:
Hurricanes and tropical storms gain their power from heated water evaporating from the ocean.
Explanation:
Brown Water Effect The brown ocean effect is an observed weather phenomenon involving some tropical cyclones after landfall. Normally, hurricanes and tropical storms lose strength when they make landfall, but when the brown ocean effect is in play, tropical cyclones maintain strength or even intensify over land surfaces.please explain me answer a b c d
Answer:
I don't know the answers of chemistry if you have an entrance question of maths so I can
[tex]\rule{2000pt}{1000000pt}[/tex]
why is extra vitamin C excreted in urine from the body but vitamin A in excess is retained in the body
Answer:
Vitamin C is water-soluble and not stored in your body
In contrast to fat-soluble vitamins, water-soluble vitamins do not get stored within the body. Instead, the vitamin C that you consume gets transported to your tissues via body fluids, and any extra gets excreted in urine ( 1 ).
Answer:
The reason vitamin C isn't stored well is because your body can't make it, and vitamin C is a water-soluble vitamin. This means it dissolves in water, and what your body doesn't use right away is excreted through urine. Thus, it is not stored in our body to a significant extent.
Explanation:
What is the role of starch in the titration reaction?
Answer:
Starch reacts with Iodine in the presence of Iodide ion to form an intensely colored blue complex, which is visible at very low concentrations of Iodine, making it a very good indicator in both direct and indirect lodometric titrations.
Explanation:
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What are the five different types of leaves? Subject: science
Answer:
Needle and Scale Leaves. This kind of leaves are mostly found in 'evergreen' trees. ...
Lanceolate Leaf. ...
Oblong Leaf. ...
Linear Leaves. ...
Cordate Leaves.
Explanation:
Answer:
Broad
Flat Leaves.
Needle and Scale Leaves.
Oblong Leaf.
Cordate Leaves.
Explanation:
Please help due tomorrow
Answer:
The gravitational force at the center of the Earth is 0.
What is chlorine iodine ?
Answer:
Chlorine Iodine is a compound made out of one Chlorine molecule and one Iodine molecule
Explanation: