Answer:
%Li-6 = 5.996% & %Li-7 = 94.004%
Explanation:
let X₁ = Li-6 & X₂ = Li-7 where Xₙ = mole fraction
X₁ + X₂ = 1 => X₁ = 1 - X₂
6·X₁ + 7·X₂ = 6.94004
=> 6(1 - X₂) + 7·X₂ = 6.94004
=> 6 - 6·X₂ + 7·X₂ = 6.94004
=> 6 + X₂ = 6.94004
X₂ = 6.94004 - 6 = 0.94004 => %X₂ = %Li-7 = 94.004%
X₁ = 1.00000 - 0.94004 = 0.05996 => %X₁ = %Li-6 = 5.996%
Samantha is investigating the densities of several liquids. Which action is the result of her creative thinking ?
Answer:
A. Poe
Explanation:
pagmali sorry na Lang
What is the change in oxidation number of bromine in the following re-dox reaction Cl 2 +2HBr 2HCl+Br 2 A -2;0 B) -1;0 C) 0: -1 D) 0;-2
Answer:
ANSWER
ANSWER: +1
EXPLANATION
What is the change in oxidation number of bromine in the following re-dox reaction Cl 2 +2HBr 2HCl+Br 2 A -2;0 B) -1;0 C) 0: -1 D) 0;-2
for Cl 2 +2HBr 2HCl+Br 2 , the Cl in Cl2 is reduced from "0" to
"-1" and the Br in HBr is oxidized from "-1" to "0"
So the change in oxidation number is +1
Question 1 (2 points)
Which option can be classified as a pure substance?
Question 1 options:
heterogenous mixture
solution
homogenous mixture
compound
Question 2 (2 points)
Law of conservation of mass states that:
Question 2 options:
matter is destroyed
matter does not change
matter is neither created nor destroyed
matter is created
Question 3 (2 points)
What is a property of bases?
Question 3 options:
all of the above
Sour taste
Slippery touch
Ability to form hydronium ions+
Question 4 (2 points)
Which property do solutions with low pH values have?
What does it mean to have a neutral pH? - Aseptic Health
Question 4 options:
have a -OH group
feels slippery
turns litmus paper blue
tastes sour
Question 5 (2 points)
How do the products of chemical reactions compare to their reactants?
Question 5 options:
The products often have completely different properties than the reactants.
The products are usually more toxic than the reactants.
The products usuallyhave more mass than the reactants.
The products usually have more atoms than the reactants.
Question 6 (2 points)
Which of the following is an example of a physical change?
Question 6 options:
Water freezing into ice.
A piece of wood burning.
A toy car rusting.
Zinc producing hydrogen gas when mixed with water.
Question 7 (2 points)
What might happen if you mixed a strong acid with an equally strong base?
Question 7 options:
You would see an explosive chemical reaction.
The base would destroy the acid.
You'd wind up with a pH-neutral salt and water.
The acid would destroy the base.
Question 8 (2 points)
In the equation shown, what are the reactants?
2H2+O2àH2O
Question 8 options:
Hydrogen and oxygen molecules (2H2 and O2 )
Ice crystals
Hydrogen atoms (H)
Water molecules (H2O)
Question 9 (2 points)
Which phrase most accurately describes a chemical change?
Question 9 options:
A change in form
A change in taste
A change on the molecular level
A change in appearance
Question 10 (2 points)
What does it mean when there is a physical change?
Question 10 options:
A new substance has been formed.
Matter has changed from one substance into a new substance.
Matter has changed size, shape or form
Matter has changed on the molecular level.
help pls ill give 20 points!
Answer:
1) Compound
2) Matter is neither created nor destroyed
3) All of the above
4) Turns litmus paper blue
5) The products often have completely different properties than the reactants.
6) Water freezing into ice
7) You'd wind up with a pH-neutral salt and water.
8) Hydrogen and oxygen molecules (2H2 and O2 )
9) A change on the molecular level
10) Matter has changed size, shape or form
Answer:
compoundmatter is neither created nor destroyedSlippery touchtastes sourThe products often have completely different properties than the reactants. Water freezing into ice. You'd wind up with a pH-neutral salt and water. Hydrogen and oxygen molecules (2H2 and O2 ) A change on the molecular level Matter has changed size, shape or formExplanation:
A. An atom neutral (one with 0 extra charge)?
Answer:
Neutron is the correct answer.
How long does it take far Uranus to complete one revolution (orbit) around the sun?
what is an electron ?state it's relatively mass and charges.
Answer:
a stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.
mass: 9.1093837015 × 10−31 kg
charges: fundamental physical constant expressing the naturally occurring unit of electric charge, equal to 1.602176634 × 10−19 coulomb.
Explanation:
good luck !<3
in what states of matter are the atoms constantly moving in a substance or material?
Answer:
LIQUIDExplanation:
A substance that flows and keeps no definite shape because its molecules are loosely packed and constantly moving. It takes the shape of its container but maintains constant volume.
In an AP Chemistry laboratory, students were given two unlabeled beakers and told that one of the beakers contained 1.0g of solid CaCO3 and the other contained
1.0g of solid AgNO3. They were told to devise an experiment to identify which compound was which. A student did so by adding 50 mL of distilled water to each beaker. Describe the student's observations that allowed him to identify each compound.
When the student adds 50 mL of distilled water to each beaker, CaCO3 will not dissolve in water while AgNO3 will dissolve completely in water.
We have to recall that according to the solubility rules, the carbonates of group two elements are insoluble in water. The solubility rules offer a convenient way of predicting the solubility of a compound in water.
When the student adds 50 mL of distilled water to each beaker, CaCO3 will not dissolve in water while AgNO3 will dissolve completely in water. This is because, the carbonates of group two elements are insoluble in water.
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chemical properties of sodium
Answer:
Density 0.97 g.cm -3 at 20 °C
Melting point 97.5 °C
Boiling point 883 °C
oxidation states +1, −1 (rare)
Explanation:
Have a nice day
Determine the rate of reaction at 50 C when the loss of mass is 0.95 g. Show your working. Give your answer to 2 significant figures.
* 20 points for who gets it *
This problem is providing information about the loss of mass for a reaction 50 °C as a function of the time elapse. Thus, when taking a look at the given graph, we can trace a horizontal line on the y-axis at 0.95 g in order to intercept it with the curve, and hence, figure out the time at which that loss of mass takes place.
Thus, we can see that when the loss of mass hits 0.95 g, the corresponding time on the graph is about 80 seconds, and hence, the rate of reaction turns out to be:
[tex]r=\frac{0.95g}{80s}\\\\r=0.012\frac{g}{s}[/tex]
Which has two significant figures as required.
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https://brainly.com/question/24072508 https://brainly.com/question/8983899how to keep apples from browning without lemon juice?
Answer:
eat
Explanation:
eat the dang apples
How many electrons are there in the N shell of an element?
[tex] \huge \mathbb \pink{ANSWER:}[/tex]
2,5 the elctrons arw there in the N shell of an element.Explanation:
Hope it helps ^•^
Each shell can contain only a fixed number of electrons: The first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on. The general formula is that the nth shell can in principle hold up to 2(n2) electrons
if the column of water in the water barometer rose to a height of 39 feet, what would the atmospheric pressure be in mm hg?
The atmospheric pressure for a column of water barometer that rose to 39 feet is 874 mmHg
From the given information, to determine the atmospheric pressure at which the column of the water barometer rose, we will need to convert the height of the water column to mmHg.
From the dimensional analysis of standard rate conversion, we know that:
1 feet = 12 inches
1 inch = 25.4 mm
1 mmHg = 13.6 mm of water.
∴
[tex]\mathbf{\implies 39 \ feet \ of \ H_2O \times \dfrac{12 \ in ch \ H_2O}{1 \ feet \ H_2O} \times \dfrac{25.4 \ mm \ H_2O}{1 \ inch \ H_2O} \times \dfrac{1 mmHg}{13.6 \ mm \ H_2O}}[/tex]
= 874.058 mmHg
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The
( )state is the lowest possible energy level that an electron can occupy.
When the electron gains energy, it may move to a higher energy level. This is called the( )
state
Answer: ground state
Explanation: The ground state, assuming you’re talking about an electron in an atom. As far as isolated leptons go, the electron is the lowest energy among the electron, muon, and tau particles. Muons and tau particles are unstable. A tau can decay into a muon or electron or other decays, while a muon can decay into an electron and associated neutrinos or gamma rays. Each has a corresponding neutrino, all of which have really, really tiny masses. P.S not copy pasted
Ground state is the lowest possible energy level that an electron can occupy. When the electron gains energy, it may move to a higher energy level. This is called the exited state.
The ground state is the lowest possible energy level that an electron can occupy within an atom. In this state, an electron is in its most stable configuration, meaning it is closest to the nucleus and has the lowest energy level available to it.
When an electron gains energy from an external source, such as absorbing a photon of light or heat, it can move to a higher energy level. This state is known as the excited state. In the excited state, the electron is located farther from the nucleus and possesses more energy than it does in the ground state. The additional energy is stored by the electron as potential energy in its increased distance from the nucleus.
The excited state is temporary. Electrons in an excited state are not stable, and they tend to return to lower energy levels (closer to the nucleus) by releasing the excess energy in the form of photons of light. This phenomenon is the basis for various processes, including fluorescence and emission spectra.
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The compound ammonium sulfate consists of two ions, NH4+ and SO42–, both of which are
a positively or negatively charged particle is called:
Answer:
A positively or negatively charged particle is called an ion.
Explanation:
Ions form when they lose or gain electrons in order to become stable by filling their octet. When an element lose an electron(s), it becomes positively charged and occpanies the symbol (+). When an element gains an electron(s), it becomes negatively charged and occpanies the symbol (-).
what is the differece between substance and matter?
Answer:
Anything that occupies space and has mass is matter but the matter that has specific composition and chemical characteristics is substance
Answer:
Substance: Something that has only 1 atom, for example; Water.
Matter: Made up of more than 1 atom, example; Humans
Explanation:
As said a substance is something that has only 1 atom like water or tin.
Matter is well almost everything in the universe, there's a reason some people say; This is Human Matter. I'm pretty sure it's somewhere in the bible too.
If you were to search it up the other persons answer would come up
How many elements are in the other metals group
Answer:
7 elements
Explanation:
Answer:
There are 7 elements
Explanation:
what is the number of electrons in a potassium atom
Answer:
19 electrons, that's what I say
What was the effect of decreasing the copper's mass?
Answer:
Decreasing the temperature of the copper made the final temperature decrease.
Heat emitted by copper reduces as copper's mass decreases. As the mass of copper lowers due to a decrease in heat gain by water, the final temperature also drops.
What is heat?The transfer of kinetic energy from an energy source to a medium, an object, or from one to the other is referred to as the creation of heat. The sun is the source of all energies. It is the natural source of solar energy, heat, and light. Thermal energy can move through three different channels: conduction, convection, and radiation.
Therefore, the increase in temperature is always proportionate to the mass of water. Thus, the final temperature will be lower if we increase the water mass. The temperature will be lower in the end. The density reduces as volume grows. Consequently, density drops as temperature rises.
Thus, heat emitted by copper reduces as copper's mass decreases. As the mass of copper lowers due to a decrease in heat gain by water, the final temperature also drops.
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I need help with this question
What are the component of science?
What are the descriptions?
How does it form?
Hope you can answer properly
^_^ ❤☺
[tex] \large \text{Answer} \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ [/tex]
1.ans: observations, questions, hypothesis, methods and results are the five components of scientific method.
2.ans: written account of object.
3.ans: sry I didn't get
hope my 2 answers can help you ࿐❤
Answer:
1) Sience involves six kinds of components:
• Problems
• Attitudes
• Methods
• Activities
• Conclusions
• Effects
2) Knowledge is information or information that is known or realized by someone.
3) Science form:
• Direct knowledge (direct)
• Indirect knowledge (mediated)
• Sensory knowledge (perception)
• Conceptual knowledge (conceptual)
• Particular knowledge (special)
• Universal knowledge (universal)
Explanation:
I hope this help :)
2. Which diagram represents deposition?
A liquid —>solid
B gas-> Solid
C liquid->gas
D solid—>gas
How many moles of ammonium ions are in 125 mL of 1.40 M NH4NO3 solution? ________ moles (give answer with correct sig figs in units of moles without scientific notation)
The number of mole of ammonium ion, NH₄⁺ in the solution is 0.175 mole
We'll begin by calculating the number of mole of NH₄NO₃ in the solution. This can be obtained as follow:
Volume = 125 mL = 125 / 1000 = 0.125 L
Molarity = 1.40 M
Mole of NH₄NO₃ =?Mole = Molarity x Volume
Mole of NH₄NO₃ = 1.40 × 0.125
Mole of NH₄NO₃ = 0.175 moleFinally, we shall determine the number of mole of ammonium ion, NH₄⁺ in the solution. This can be obtained as follow:
NH₄NO₃(aq) —> NH₄⁺(aq) + NO₃¯(aq)
From the balanced equation above,
1 mole of NH₄NO₃ contains 1 mole of NH₄⁺
Therefore,
0.175 mole of NH₄NO₃ will also contain 0.175 mole of NH₄⁺
Thus, the number of mole of ammonium ion, NH₄⁺ in the solution is 0.175 mole
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How many cobalt atoms are in 2 moles of cobalt?
That means that one mole of cobalt weighs 58.9332 grams (58.9332 g/mol). Based on that information, to convert 2 moles of cobalt to grams, we multiply 2 moles of cobalt by 58.9332.
12.04428152 x [tex]10^{23}[/tex] cobalt atoms are in 2 moles of cobalt.
What are moles?A mole is defined as 6.02214076 ×[tex]10^{23}[/tex]
of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.
One mole of cobalt is equal to 6.02214076 ×[tex]10^{23}[/tex] atoms.
2 moles of cobalt is equal to 6.02214076 × [tex]10^{23}[/tex]atoms x 2
12.04428152 x [tex]10^{23}[/tex]
Hence, 12.04428152 x [tex]10^{23}[/tex]cobalt atoms are in 2 moles of cobalt.
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how many core electrons are there in a sodium atom?
Answer:
There are 13 core electrons in a sodium atom.
What does displacement reaction tell you about the reactivity of the 2 metals involved?
it tells me that one element is more reactive than the other
Explanation:
using the reactivity series. the element that come above is the most reactive e.g
potassium
sodium
calcium
magnesium....
potassium is more reactive than sodium and the following below
calcium is more reactive than magnesium since it is below it in the reactivity series.
CONCLUSION, reactivity decreases down the reactivity series and increases up the reactivity series. the example i gave is part of the reactivity series of cations but there is also for anions
Help please and thank you for who ever
Answer:the first one
Explanation:
Answer:
Ribosomes are found in both cells
A spoon. A beaker partially filled with liquid. A stirring rod. A graduated cylinder. Distilled water in a spray bottle. Which of the following tools could have become cross-contaminated during the experiment if you had not cleaned them carefully between successive tests? Spoon Beaker Stirring Rod Graduated Cylinder Distilled water in spray bottle.
Answer:
A,B,C,D
Explanation:
Answer:
A,B,C,D
Explanation:
Proof
A compound is 2. 00% H by mass, 32. 7% S by mass, and 65. 3% O by mass. What is its empirical formula? The third step is to calculate the mole ratios of the elements present. To do this, you will divide each molar amount by the smallest molar amount. The molar amounts of the elements present are:.