Answers
Answer:
1. Isotopes are atoms of an element that consist of the same number of protons but a different number of neutrons.
2. No. of protons = 13
No. of neutrons = 27 - 13
= 14
3. refer to attached file
4(a). Since the noble gases can be found in group 18 of the periodic table, it suggests that they have a complete octet (a full valence shell of electrons), and this allows them to be stable gases that show the least reactivity.
4(b). Since the number of protons and electrons are equal in an atom, the opposite charges are balanced and thus, there is no net charge on the atom (neutrons present in the atom have no charge). Hence, an atom is electrically neutral.
5. Mass no. of X = 6 + 6
= 12
Mass no. of Y = 6 + 8
= 14
6. mass number = no. of protons in the nucleus of an atom + no. of neutrons in the nucleus of an atom
atomic number = no. of protons in the nucleus of an atom
isobars = atoms of elements which have the same mass number but different atomic numbers
isotopes = atoms of elements which have the same number of protons but a different number of neutrons
Related Questions
What is the average atomic mass of the isotopes shown in the table?
Isotope Abundance (%) Mass of Isotope (amu)
Isotope-A
54.0
17.984
Isotope-B
32.0
18.985
Isotope-C
14.0
19.982
Answers
Answer:
18.58
Explanation:
From the question given above, the following data were:
Isotope A:
Abundance of A = 54%
Mass of A = 17.984 amu
Isotope B:
Abundance of B = 32%
Mass of B = 18.985 amu
Isotope C:
Abundance of C = 14%
Mass of C = 19.982 amu
Average atomic mass =?
AVERAGE = [(Mass of A × A%)/100)] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
AVERAGE = [(17.984 × 54%)/100] + [(18.985 × 32%)/100] + [(19.982 × 14%)/100]
= 9.71136 + 6.0752 + 2.79748
= 18.58
Therefore, the average atomic mass of the isotope is 18.58 amu
In a lab, a scientist mixes a purple powder-like substance and a clear liquid together. The scientist observes that the two substances begin combining together, and he notices a gas begin to bubble out of the mixture. Did the scientist witness a chemical reaction? Why or why not?
Answers
The scientist witnessed a chemical reaction because a gas was evolved when the two substances were mixed.
A chemical reaction is the same as a chemical change. When a chemical change occurs, atoms recombine to form new substances. Certain occurrences may accompany a chemical reaction such as;
Change in colorEvolution of gasAppearance of a solid in an aqueous phase reactionSudden change in the temperature of the system.When the scientist mixed purple powder-like substance and a clear liquid together, he noticed that a gas began to bubble out of the mixture. This implies that new substance has been formed so a chemical reaction has taken place.
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20.What do carbon and silicon have in common?
a.They belong to the same column (family), therefore they have the same number of valence electrons.
b.They belong to the same column (family), therefore they have the same number of total electrons.
c.They belong to the same column (family), therefore they have the same number of energy levels.
d.They belong to the same column (family), therefore they have the same number of protons.
Answers
a.They belong to the same column (family), therefore they have the same number of valence electrons.
A gas at 127 celsius and 10.0 L expands to 20.0 L. What is the new
temperature in kelvin? (You must convert to Kelvin before calculating
this problem
Answers
Answer:
800.3 Kelvin
Explanation:
127°C = 400.15 Kelvin (because 127 + 273.15)
Charles Law:
[tex]\frac{V1}{T1} = \frac{V2}{T2}[/tex] Thus, [tex]\frac{10.0 L}{400.15 K} = \frac{20.0 L}{T2}[/tex]
Then, work out the math algebraically.
T2 = 20.0 / (10.0/400.15)
= 20.0 / 0.02499...
= 800.3 Kelvin
This is assuming the pressure remains constant.
How many liters are there in 28g of B?
Answers
The volume is 58.1
The moler mass is 10.8
Molar mass details
10.81B (1*10.81)
Hope this helps
Look carefully at the list of objects and order
them from smallest to largest.
ant
atom
cell
dust particle
ping pong ball
Explain why you have them in this order. Be sure
to use a 5 complete thoughts.
:
Answers
Answer:
Atom, cell, dust particle, ant, ping pong ball
Explanation:
Firstly, atoms make up all matter, including each of the items on that list. The only things smaller than atoms are the parts of the atom itself, protons, neutrons and electrons. Because none of those are on that list, atoms have to be the smallest. Next smallest is the cell. Cells are made up of atoms, but they also in part make up dust. You can see a dust particle with the naked eye, but in order to see a cell you must use a microscope. Thus, cells are smaller than dust particles. Next is an ant. Obviously, an ant is bigger than a speck of dust, and is made up of cells and atoms. Lastly all you have is the ping pong ball, which is much larger than the rest of the items. Hope this helps!
All matter, including each thing on the list, is made up of atoms. The protons, neutrons, and electrons that make up an atom are the only particles smaller than atoms.
Thus, Atoms must be the tiniest object because none of those are included in that list. The cell is the next smallest. Atoms make up cells, but dust also makes up a portion of them.
A dust particle can be seen with the unaided eye, but a microscope is required to see a cell.
Cells are hence smaller than dust particles. An ant comes next. Of course, an ant is composed of cells and atoms and is larger than a particle of dust.
Thus, All matter, including each thing on the list, is made up of atoms. The protons, neutrons, and electrons that make up an atom are the only particles smaller than atoms.
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1s2, 2s2, 2p6, 3s2, 3p6, 4s2
After this atom gains or loses valence electron/s, what will the oxidation number be?
Answers
Answer:
if it gains then it will be negative to whatever number it has gained and the reverse for when it loses
Explanation:
the number of molecules present in 0.036g of water
Answers
Answer:
5
Explanation:
Please help fast. I will give brainliest.
Answers
Answer:39 min
Explanation:
Sexual reproduction involves male and female sex cells known as ______.
Answers
Answer:
Sexual reproduction involves male and female sex cells known as - Gametes
Explanation:
In sexual reproduction new organisms are produced from the fusion of a male sex cell with a female sex cell. This fusion of gametes is called fertilisation. Sex cells are also known as gametes. Male gametes are made by male reproductive structures. Female gametes are made by female reproductive structures.
What are the three types of Covalent bonds? and what is the difference between them?
Help!!!
Plsss fastt
Answers
Answer:
Covalent bonds can be single, double, and triple bonds.
Explanation:
Single bonds occur when two electrons are shared and are composed of one sigma bond between the two atoms. Double bonds occur when four electrons are shared between the two atoms and consist of one sigma bond and one pi bond.
Heavier noble gases are able to form compounds with other elements under specific conditions because their valence ____are farther from the _____
Answers
Answer:
Heavier noble gases are able to form compounds with other elements under specific conditions because their valence electrons are farther from the nucleus.
Explanation:
The name of noble or inert gas is due to the lack of reactivity with other elements. This is due to its electronic configuration, because its outermost shell or valence shell is always complete, without the need to share, give or receive electrons forming bonds. That is, its outer layer is so stable that the element tends not to react with others except in very specific cases.
These exceptions generally involve the heavier noble gases, such as xenon or radon, capable of forming compounds with fluorine and oxygen. This is because the heavier noble gases have more electron shells than the lighter ones. This characteristic causes the outermost electrons to experience a "shielding" effect due to the action of the inner electrons, and they can then be ionized more easily, since the attraction they receive from the positive charges of the nucleus is weaker. That makes the ionization energy low enough to form stable compounds with more electronegative elements, such as fluorine and oxygen.
Heavier noble gases are able to form compounds with other elements under specific conditions because their valence electrons are farther from the nucleus.
Which have a mass of 0 amu ?
I give Brainliest!!!!
Answers
Answer:
Electrons
Explanation:
Protons and Neutrons have an amu of 1
Answer:
c. Electrons
Explanation:
Electrons are found outside the nucleus and are the lightest.
Energy that is stored is called potential energy. Take a round ball that is at rest at the top of the hill. The ball has a lot of potential energy, but no kinetic energy because it is not moving. Once the ball is released and it begins to roll, the potential energy the ball had initially is transformed into kinetic energy. The higher the ball is placed, the ____ potential energy it will have.
A-more B-less
Answers
4. How is a lead storage battery recharged?
a. It is heated up.
b. The pressure on it is increased.
c. A direct current is applied to it.
d. A magnet is held close to it.
Answers
A chemist analyzes two samples. One sample contains 14g of element x and 6.0 g of element y. The second sample contains 28 g of element x and samples are the same substance
Answers
Answer:
Explanation:
Here's the complete question:
A chemist analyzes two samples.One sample contains 14g of element x and 6.0g of element y.The second sample contains 28g of element x and 6.0g of element y. Does it appear that the two samples are the same substance?
The two samples that we are given in the question are different. They are not the same thing because we can deduce that their components ratio are different.
Sample One contains 14g of element x and 6.0g of element y. The ratio of element x to y is 14/6 = 7/3 = 7:3.
Sample Two contains 28g of element x and 6.0g of element y. The ratio of element x to y is 28/6 = 14/3 = 14:3.
Therefore, they have different ratio for their components and are therefore not thesame.
Is hydrogen bond an attraction between polar molecules
Answers
Answer:
No because if there was an attraction hydrogen would not do it's function
Will a nucleus of Zn-65 be stable or unstable?
Answers
Answer:
Unstable
Explanation:
Pascal’s Law states that when pressure is applied from an outside source to a contained fluid, the force is
a. transferred through the liquid in a single direction
b. transferred through the liquid in the opposite direction
c. transferred unequally through the liquid in all directions
d. transferred equally through the liquid in all directions
Answers
Answer:
a
Explanation:
Answer:
a.....................
which of the following indicates the cathode rays has a large charge to mass ratio?
Answers
Answer:
Gggg
Explanation:
The indication of the cathode rays that has a large charge to mass ratio is there were deflected towards a positive electrode. The correct option is b.
What are cathode rays?Cathode rays are the rays that move through the negatively charged electrode the cathode charge to the positively charged electrode which is the anode charge in a vacuum tube.
These rays travel through a pipe in a straight line with speed when there is voltage is applied. They are also called electron beams. There is a cathode ray tube, CRT, which is a vacuum tube on which cathode rays travel.
So, the correct option will be for the cathode rays would be deflected towards a positive charge anode.
Therefore, the correct option is b, there were deflected towards a positive electrode.
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The question is incomplete. Your most probably complete question is given below:
They were easily deflected
There were deflected towards a positive electrode
They were deflected towards a negative electrode
They caused a fluorescent screen to glow
How cold does it really get on Pluto's moon, Charon? (I know this is not a Chem question per se, but is there no Earth Science, nor Space, nor Astronomy, nor General Science category on Brainly?)
Answers
Answer:
Explanation:
After various studies and experiments conducted on Pluto's moon, Charon it has been determined that it gets to minus 459.67 degrees Fahrenheit which would be equivalent to minus 273.15 degrees Celsius. This is the coldest temperature that scientists have registered for Charon. This temperature is nearing absolute zero and puts it colder than Pluto itself since Pluto's temperature is believed to get to minus 400 degrees Fahrenheit which is equivalent to minus 240 degrees Celcius.
Fire ants move in to a new environment with the lizards.what will most likely happen to the lizard population over the next several years
Answers
Answer:
Some lizards in the eastern U.S. have adapted to invasive fire ants -- which can bite, sting, and kill lizards -- reversing geographical trends in behavioral and physical traits used to avoid predators. A new study describing this reversal appears online on November 29, 2018, in the journal Global Change Biology and reveals that new environmental challenges can override the historical influences that originally determined geographical trends in traits.
"Rapid environmental change, be it from changing climate or the introduction of invasive species, is putting a lot of pressure on native species," said Christopher Thawley, graduate student at Penn State at the time of the study and first author of the paper. "Usually when researchers look at how native species might respond to these kinds of threats, they might measure one characteristic of the animal and at one or a few sites. In this study, we looked at three separate characteristics of eastern fence lizards from thirteen sites spanning a thousand miles and found that these lizards are capable of adapting in a concerted way to meet the threat of invasive fire ants, and in a relatively short time frame."
Explanation:
How can you prove that air is a matter ?
Answers
Answer:
One way to prove that air is made of matter is to blow up a balloon. Before you add air into the balloon, it is empty and shapeless. When you puff air into it, the balloon expands, so you know it is filled with something—air is taking up space. You'll also notice that a balloon filled with air sinks to the ground.
Explanation:
What evolution was evident in Darwin's finches?
1. beak type
2. leg muscles
3. wing span
4. eyesight
Answers
explanation:
i’m not 100% bc you didn’t give any info on darwin
Answer:
sorry I don't know the answer hope you understand
which is the odd man out? diamond,coal, graphite, bronze.answer with an explanation
Answers
define p-block element?
Answer:
[tex]\boxed {\boxed {\sf D. \ Bronze}}[/tex]
Explanation:
Let's analyze the answer choices.
The first answer choices. diamond, coal, and graphite, all have something in common. They are allotropes of carbon. They are made of the same element, but each has a different arrangement of atoms, which leads to different properties.
Bronze is an alloy of copper, tin, and other metals. It's not an allotrope of carbon or related to the other answer choices. Therefore, it is the odd one out.
The human body has several major systems. Most body systems have multiple functions. Which of the following is NOT a major function of the musculoskeletal system?
A turning food into energy
B helping the lungs take in air
C helping the stomach digest food
D moving the bones of the skeleton
Answers
Answer:D
Explanation:
i got it right LOL
Among the given options, the one which is not a major function of musculoskeletal system is helping the lungs take in air. All others including, energy, digestion, movement of bones etc. are its function.
What are the functions of musculoskeletal system ?The musculoskeletal system in human body is composed of muscles and bones. The bones in our body are wrapped by the muscles. Muscles helps for the smooth movement of bones.
Muscles convert the chemical energy from food into kinetic energy and use it for the movement of muscles and bones. Muscles contraction needs intake of energy.
The contraction and relaxation of smooth muscles helps for the easy movement of food through the digestive track. Musculoskeletal system also helps for the movement of other organ system. Hence, option b is not the major function of this organ system.
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Explain why the metals conduct electricity.
Write in your own words.
Please don't copy-paste from the internet.
Answers
Answer:
Metals conduct electricity because they have free Electrons in them which helps the current to move eaisily
what is light energy
Answers
Answer:
Light energy is a form of electromagnetic radiation. Light consists of photons, which are produced when an object's atoms heat up.
Explanation:
Answer:
Light energy is a kind of kinetic energy with the ability to make types of light visible to human eyes. Light is defined as a form of electromagnetic radiation emitted by hot objects like lasers, bulbs, and the sun. Light contains photons which are minute packets of energy.
Explanation:
hope it's helpful for you.
can someone help w/ chem plzz
Answers
Answer:
my answer I think is tetrahedral
The pH of a solution is 8. Some hydrochloric acid is added to the solution. Suggest the pH of the solution after mixing. pH=.......??
Answers
Answer:
By adding acid to hydrogencarbonate you create a large concentration of CO2 in solution causing the solution to be highly supersaturated. This keeps the pH down as CO2 is in equilibrium with carbonic acid. During the day long mixing the excess CO2 strips off and as acid leaves the solution the pH increases.
Explanation:
Hope it helps
A solution with a pH of 8 will have its pH reduced with the addition of hydrochloric acid.
What is pH?It is the degree of acidity or alkalinity of solutions.
pH ranges from 0 to 14 with 7 being a neutral pH. Any pH below 7 is acidic while above 7 is basic.
Thus, a pH of 8 is basic and the addition of hydrochloric acid will reduce it towards 7 or even below it.
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