Answer:
After 7.648 days, you will see one quarter.
Explanation:
1 → 0.5 → 0.25
Since half life of radon-222 is 3.824 days, you need twice this time to get one quarter at the end.
2 ⋅ 3.824 = 7.648 days.
Neturally an atom is neutral in charge why
Answer
Explanation:
an atom is usually define as a perfect balance of electrons and protons
8. Which word best describes the element in box number 2?
a а Brittle
b Gas
С Semiconductor
d. Shiny
Answer:
gas
Explanation:
i think it might be gas
What happens in the nucleus when a lithium atom becomes an ion
Answer:
An atom that gains a negative electron, it becomes a negative ion. ... A lithium atom has 3 protons and 3 electrons. It can lose one of its electrons, making it an ion. It now has more positive protons than electrons so it has an overall positive charge.
Answer:
This means a Lithium atom formed into a Lithium ion by losing one of its electrons. It has three electrons and three protons to begin with. So when it loses or gains one the amount isnt equal, that is why it becomes an ion. If it gained electrons it would have a negative charge on the nulcleus, though if it lost electrons it would have a positivec charge. Hope this helped!!
Water molecules are polar because the
water molecule has a linear shape.
water molecule has a bent shape.
oxygen atom has fewer electrons around it.
hydrogen atom forms an ionic bond with oxygen.
Answer: B (water molecule has a bent shape)
Explanation:
Water molecules are polar molecules because of their shape. Water molecules have one side that is positively charged due to hydrogen atom which is partially positive and the other side which is negatively charged, due to the oxygen atom.
When two molecules get close to each other the polar forces of attraction brings them close to each other. Oxygen bonds with several hydrogen atoms in the other water molecules resulting to hydrogen bonds.
Answer:
the answer is B
Explanation:
4. Know the location of metals, non-metals and metalloids
Answer:
The metals are to the left of the line (except for hydrogen, which is a nonmetal), the nonmetals are to the right of the line, and the elements immediately adjacent to the line are the metalloids.
Hope this helped
Where do we live a.Troposphere b.Thermosphere c. Mesosphere D.Stratosphere
Answer:
troposphere
Explanation:
Answer:
Hello!!! Princess Sakura here ^^
Explanation:
We live in the troposphere since 99% of the water vapor in the atmosphere is found here.
identify the elements given the orbital diagrams listed below.
Answer:
See explanation.
Explanation:
1. There are 8 electrons. Elements that end with 2p orbitals are in the 2nd period (aka row) of the periodic table. Elements that have 4 electrons in 2p are in the 16th group (aka column) (column 16 may also be referred to as 6A) of the periodic table. So looking at row 2, column 16, we can see that the first diagram is of O, Oxygen.
2. 8 electrons. This is the same diagram as the one above.
3. 13 electrons. Elements ending with 3p are in period 3. Elements with 1 valence electron in a p orbital are in group 13 (aka group 3A).
4. 7 electrons. We already know 2p is period 2. 3 valence electrons in a p orbital means that it is in group 15/group 5A.
I did not write the answers for #3 and 4 but they can be easily found on a periodic table with the info I gave.
The elements given the above orbital diagrams are as follows:
Oxygen
Oxygen
Aluminum
Nitrogen
In first case,
There are total 8 electron and the electronic configuration is 1s2 2s2 2p4. The element which end up with 2p configuration belongs to 2nd period. It have four electron in their outermost shell so, it belongs to 16th group, So the element is Oxygen.
In the same way we will find the elements for rest of the cases.
Thus, we reach to the conclusion that the elements given the above orbital diagrams are as follows:
Oxygen
Oxygen
Aluminum
Nitrogen
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Which of the following is NOT
matter
Air , steam, heat , cow
Answer:
air
Explanation:
Answer:
Heat
Explanation:
Heat is a transfer of energy, but it is not made of matter. If you were talking about fire, fire is matter. But the heat from it isn't.
Can someone help me quickly?
When comparing bromine to chlorine, bromine has
A. Fewer protons in its nucleus.
B. A weaker effective nuclear charge
C. More valence electrons
D. More electron shielding
Explanation:
I'm pretty sure the answer is D
Which is the name of O3?
dioxide
oxygen
trioxygen
monoxide
The answer is C, Trioxygen
The name for O₃ molecule is trioxygen as it is made up of three oxygen atoms.
What is an atom?An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
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Which elements are likely to close electrons?
Answer:
Explanation:
In general, metals will lose electrons to become a positive cation and nonmetals will gain electrons to become a negative anion. Hydrogen is an exception, as it will usually lose its electron. Metalloids and some metals can be can lose or gain electrons.
what is the identity of the element that produced the unknown emission spectrum
Answer:
The emitted light can be observed as a series of colored lines with dark spaces in between; this series of colored lines is called a line or atomic spectra.
Explanation:
What is the mass of 4.39 mol Na?
Answer:
101 g Na
Explanation:
To convert between moles and grams, you have to use the molar mass of the substance. The molar mass of sodium is 22.99 g/mol. You use this as the unit converter.
[tex]4.39molNa*\frac{22.99gNa}{1molNa} = 100.9261gNa[/tex]
Round the number to the lowest number of significant figures; 101 g Na.
The mass of 4.39 moles of sodium (Na) is 100.97grams.
HOW TO CALCULATE MASS:The mass of a substance can be calculated by multiplying the number of moles in the substance by its molar mass. That is;Mass = no. of moles × molar mass
According to this question, there are 4.39 moles of Na. The molar mass of Na is 23g/mol.Mass of Na = 4.39 × 23
Mass of Na = 100.97grams.
Therefore, mass of 4.39 moles of sodium (Na) is 100.97grams.
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How will you increase the solubility of a gases in a liquid solvent?
A. Decrease the Temperature
B. Decrease the Pressure
C. Increase the Temperature
D. Increase the Pressure
Answer:
increase the temperature
Explanation:
The solubility of a gas in a liquid will increase if: Lower the temperature of the solution , and therefore, lower the kinetic energy of the gaseous particles so they can escape the liquid phase less often.
This method uses the different densities of the components to separate them
A. decantation
B. filtration
C. distillation
D. none of these
Answer:
D
Explanation:
none of these is the answer
Answer: The answer is: D
Explanation: none of these
Which part of Earth absorbs the most sunlight? brainly
Answer:
the answer is A)Oceans
Explanation:
1. Calculate the average atomic mass of iron if its abundance in nature is 15%-iron-55 and
85% iron-56
The average atomic mass of iron : 55.85 amu
Further explanationThe elements in nature have several types of isotopes
Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
An atomic mass unit = amu is a relative atomic mass of 1/12 the mass of an atom of carbon-12.
The 'amu' unit has now been replaced with a unit of 'u' only
Atomic mass is the average atomic mass of all its isotopes
atomic mass X = mass isotope 1 . % + mass isotope 2.% ...
The average atomic mass of iron
[tex]\tt =0.15\times 55+0.85\times 56\\\\=\boxed{\bold{55.85~amu}}[/tex]
The average atomic mass of iron : 55.85 amu
Calculation for average atomic mass:Isotopes are atoms whose atoms have the same number of protons while still having a different number of neutrons.
An atomic mass unit = amu is a relative atomic mass of 1/12 the mass of an atom of carbon-12.
The 'amu' unit has now been replaced with a unit of 'u' only
Atomic mass is the average atomic mass of all its isotopes.
Atomic mass X = mass isotope 1 * Mas % + mass isotope 2* Mass %
The average atomic mass of iron:
=0.15 * 55 + 0.85 * 56
=55.85 amu
Thus, the average atomic mass of iron : 55.85 amu
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Name the laws for 1,2, and 3
Answer:
1. Boyle's law
2. Charle's law
3. Ideal Gas law
Explanation:
Is steam a water , oxygen or hydrogen molecule ?
Answer:
In thermolysis, water molecules split into their atomic components hydrogen and oxygen. For example, at 2200 °C about three percent of all H2O are dissociated into various combinations of hydrogen and oxygen atoms, mostly H, H2, O, O2, and OH.
Explanation:
Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? a. The chlorofluorocarbons act like ultraviolet radiation causing large amount of ozone to be produced. b. The chlorine from the chlorofluorocarbons reacts with free molecules of oxygen causing a stop in ozone production. c. Free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone. d. Chlorofluorocarbons absorb ultraviolet radiation, preventing the formation of ozone.
Answer:
Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? Free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone.
Explanation:
The statement for small quantities of chlorofluorocarbons so harmful to the ozone layer is "Free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone."
What is ozone layer?The ozone layer is a thin layer of air in the Earth's atmosphere that absorbs nearly all of the sun's damaging UV radiation.
What is CFCs?CFCs (chlorofluorocarbons) are harmless and nonflammable compounds made up of carbon, chlorine, and fluorine atoms.
The earth's protective ozone layer is destroyed by chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and halons, which shield the earth from damaging ultraviolet (UV-B) rays released by the sun. CFCs and HCFCs also warm the earth's lower atmosphere, causing global climate change.
When some substances are exposed to high UV radiation in the stratosphere, they emit chlorine or bromine. Ozone-depleting chemicals are compounds that contribute to ozone depletion (ODS). Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), carbon tetrachloride, and methyl chloroform are examples of ODS that produce chlorine. Halons and methyl bromide are two ODS that emit bromine.
Because there isn't much ozone in the atmosphere, what little there is is critical for protecting the Earth's surface from excessive UV light from the Sun. It turns out that it reacts with chlorine, which means that chlorine effectively eliminates ozone.
When the chlorine in CFCs combines with ultraviolet light, it releases chlorine, which then reacts with ozone, reducing the protection humans get from ultraviolet light, allowing more CFCs to release chlorine, and so on. Multiple ozone molecules will interact with one free chlorine atom, which is free because UV light has hit the CFC molecule. As a result, the damage it can cause is likely to be significantly more than you might imagine.
Hence the correct option is c.
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Which example illustrates public scientific communication?
O A scientist collaborates with other scientists to plan an experiment.
O Ascientist sends a preview copy of a journal article to some colleagues.
O A federal government agency holds a press conference to describe the response to and the dangers of a new virus
epidemic,
A federal government agency publishes an article in a professional scientific journal detailing technical details of a
new virus
Answer:
D. A federal government agency publishes an article in a professional scientific journal detailing technical details of a new virus.
Explanation:
Public scientific communication is a way used by scientists to make the audience able to understand the basics of science to communicate an informed decision. There are several skills under public scientific communication that include connect with the public, talk to journalists, make science understandable, and understand the audience.
The best way to connect with the audience is to publish an article in a professional scientific journal because mostly journals are peer-reviewed having standard of quality.
A federal government agency informing about a new virus through an article in a professional scientific journal is the best way of public scientific communication as it will be for a specific audience along with a standard of quality.
Hence, the correct answer is "D".
Chloe is training for her first half-marathon, which requires her to run 21.1 km. Before she runs, she carefully chooses the foods that will give her the energy her body requires for the race. She stands still at the starting line, then she starts running, her body warming up as she runs. Which three energy transformations take place in this example? Potential energy to kinetic energy Chemical energy to thermal energy Chemical energy to kinetic energy Mechanical energy to chemical energy
Answer:
The transformation is of chemical energy (use the ATP molecule as a resource) which is then transformed into mechanical energy (muscle contraction) and finally transformed into thermal energy (increase in body temperature, or sweating)
Explanation:
Energy is never lost, it is always transformed, that is why energy is yielding electronic movement and expressing itself in different ways, first as chemical energy, then as mechanical energy, and lastly as thermal energy.
It is important to clarify that the energy source of all this transformation is food and energy reserves.
when Lithium forms an ionic compound with carbonate, how many of each ion is needed?
Answer:
Two Lithium ions and one carbonate ion
Explanation:
Let us look at this equation;
Li2CO3(s) ------->2Li^(aq) + CO3^2-(aq)
We can see that each unit of Li2CO3 has two lithium ions and one carbonate ion.
Let us not forget that Li has a valency of 1 while carbonate ion has a valency of 2. Exchange of valencies gives the final formula of the compound.
Answer:
Two Lithium ions and one carbonate ion
Explanation:
-79.6 -80 -81.2. is the correct answer
Valence electrons determine blank
Answer:
the element's chemical properties and whether it may bond with other elements.
Explanation:
what is the mass of a 7.91 cm cubed piece of lead having a density of 11.34 g/cm cubed
Answer:
The answer is 89.70 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
density = 11.34 g/cm³
volume = 7.91 cm³
We have
mass = 11.34 × 7.91 = 89.6994
We have the final answer as
89.70 gHope this helps you
2. What types of organisms have cells with very large vacuoles?
Animals
Plants
Ο Ο Ο Ο.
Bacteria
Fungi
CLEAR ALL
Which food molecules are outside of the tube
Answer:
Absorption
Explanation:
I think from Quizlet
How do cells use lipids and carbohydrates?
Answer:
Animals tend to use carbohydrates primarily for short-term energy storage, while lipids are used more for long-term energy storage. Carbohydrates are stored as glycogen in animals while lipids are stored as fats (in plants carbohydrates are stored as cellulose and lipids as oils)
Explanation:
hope this helps!
Answer:
Explanation:
Animals tend to use carbohydrates primarily for short-term energy storage, while lipids are used more for long-term energy storage. Carbohydrates are stored as glycogen in animals while lipids are stored as fats (in plants carbohydrates are stored as cellulose and lipids as oils)