Answer:
a
Explanation:
the substance that exists
a substance that cannot be separated into simpler substances
Answer:
element
Explanation:
hope this helps
Explanation:
Elements are pure substances that cannot be broken down into simpler substances by ordinary chemical means.
What is the empirical formula of a molecule containing 65.5% carbon, 5.5% hydrogen, and 29.0% oxygen
what happens when ice changes to water the link up of the atoms
Answer:
Removing heat causes water (a liquid) to freeze to form ice (a solid). When water changes to a solid or a gas, we say it changes to a different state of matter. ... This causes the hydrogen atoms in one water molecule to be attracted to the oxygen atom in another water molecule.
Explanation:
11.Three atoms of element X react with an element(s) Y from group VIA. What
would be the chemical formula between X and Y.
Element “X” belongs to family 2A, meaning it is part of the family that includes elements such as Be and Mg. These elements will all have 2 valence electrons and can be represented by the following Lewis diagram:
Element “Y” belongs to family 5A, meaning it is part of the family of elements that includes elements such as N and P. These elements will all have 5 valence electrons and can be represented by the following Lewis diagram:
Atoms from these two families will usually react with each other by losing or gaining valence electrons to create stable ions (an ion is what we call an atom/particle that has a charge). These stable ions form by the atoms either losing or gaining electrons until they have the same number of valence electrons as the nearest Noble Gas. This means that each ion will have a full valence shell (usually consisting of 8 electrons), often referred to as a “stable octet”, and this process of creating stable ions is often called the “octet rule”.
Atoms with fewer that 4 valence electrons will normally have a weak hold on their valence electrons and will tend to lose their valence electrons when forming ions.
Atoms with 4 or more valence electrons will normally have a strong hold on their valence electrons and will tend to gain electrons when forming ions.
The charge on the ion arises from the fact that, initially, the atom is electrically neutral because it has the same number of electrons (negative charges) as protons (positive charges). By losing electrons, the atom will end up with more protons (positive charges) than electrons (negative charges) and will form an ion with an overall positive charge. By gaining electrons, the atom will end up with more negative electrons than positive protons becoming an ion with an overall negative charge.
So, an atom of element “X”, with only 2 valence electrons, must lose its 2 valence electrons (which will be gained by element “Y”) to form a stable ion with a 2+ charge (losing two electrons leaves the ion with 2 more positive charges (protons) than negative charges, so a net charge of 2+).
An atom of element “Y”, with 5 valence electrons, must gain 3 electrons (from element “X”) to form a stable ion with a 3- charge (gains 3 extra negative charges).
We can show this process using Lewis diagrams:
From this set of diagrams you can see that in order to create stable ions of both “X” and “Y” we need these atoms to react with each other in a 3:2 ratio (we need 3 atoms of X for every 2 atoms of Y). This means that the resulting chemical formula of the compound will be:
Now, we will look at a short cut that can help you figure this out without having to draw Lewis diagrams.
Compounds are electrically neutral, meaning they must contain equal numbers of positive and negative charges. For compounds consisting of oppositely charged ions, this means that the total charge of the negative ions must be equal to the total charge of the positive ions. In other words the ions must combine in a ratio that makes their charges add to zero.
If we look at the compound we just made, X3Y2, we can confirm this:
So, now you can you predict the formula of simple ionic compounds:
from the family of elements, determine the number of valence electrons each element has
determine the charge of the ions that each atom will form using the octet rule (or look on the periodic table, most will tell you the stable ionic charges that each element can form)
determine the ratio of positive ions to negative ions that results in an overall charge of zero
Example,
What is the formula of a compound produced when an element from family 3A combines with an element from family 7A?
What experiments did Neils Bohr do for the atomic theory?
Answer(s):
Atomic model
Bohr's greatest contribution to modern physics was the atomic model. The Bohr model shows the atom as a small, positively charged nucleus surrounded by orbiting electrons.
Bohr was the first to discover that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element.
The chemical element bohrium (Bh), No. 107 on the periodic table of elements, is named for him.
Liquid droplet theory
Bohr's theoretical work contributed significantly to scientists' understanding of nuclear fission. According to his liquid droplet theory, a liquid drop provides an accurate representation of an atom's nucleus.
This theory was instrumental in the first attempts to split uranium atoms in the 1930s, an important step in the development of the atomic bomb.
Despite his contributions to the U.S. Atomic Energy Project during World War II, Bohr was an outspoken advocate for the peaceful application of atomic physics.
Quantum theory
Bohr's concept of complementarity, which he wrote about in a number of essays between 1933 and 1962, states that an electron can be viewed in two ways, either as a particle or as a wave, but never both at the same time.
This concept, which forms the basis of early quantum theory, also explains that regardless of how one views an electron, all understanding of its properties must be rooted in empirical measurement. Bohr's theory stresses the point that an experiment's results are deeply affected by the measurement tools used to carry them out.
Bohr's contributions to the study of quantum mechanics are forever memorialized at the Institute for Theoretical Physics at Copenhagen University, which he helped found in 1920 and headed until his death in 1962. It has since been renamed the Niels Bohr Institute in his honor.
Explanation:
Niels Bohr was one of the foremost scientists of modern physics, best known for his substantial contributions to quantum theory and his Nobel Prize-winning research on the structure of atoms.
Born in Copenhagen in 1885 to well-educated parents, Bohr became interested in physics at a young age. He studied the subject throughout his undergraduate and graduate years and earned a doctorate in physics in 1911 from Copenhagen University.
While still a student, Bohr won a contest put on by the Academy of Sciences in Copenhagen for his investigation into the measurements of liquid surface tension using oscillating fluid jets. Working in the laboratory of his father (a renowned physiologist), Bohr conducted several experiments and even made his own glass test tubes.
Bohr went above and beyond the current theory of liquid surface tension by taking into account the viscosity of the water as well as incorporating finite amplitudes rather than infinitesimal ones. He submitted his essay at the last minute, winning first place and a gold medal. He improved upon these ideas and sent them to the Royal Society in London, who published them in the journal Philosophical Transactions of the Royal Society in 1908, according to Nobelprize.org.
His subsequent work became increasingly theoretical. It was while conducting research for his doctoral thesis on the electron theory of metals that Bohr first came across Max Planck's early quantum theory, which described energy as tiny particles, or quanta.
In 1912, Bohr was working for the Nobel laureate J.J. Thompson in England when he was introduced to Ernest Rutherford, whose discovery of the nucleus and development of an atomic model had earned him a Nobel Prize in chemistry in 1908. Under Rutherford's tutelage, Bohr began studying the properties of atoms.
Bohr held a lectureship in physics at Copenhagen University from 1913 to 1914 and went on to hold a similar position at Victoria University in Manchester from 1914 to 1916. He went back to Copenhagen University in 1916 to become a professor of theoretical physics. In 1920, he was appointed the head of the Institute for Theoretical Physics.
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What type of bond is between NaCL?
Answer:
Ionic Bonds
Explanation:
Ionic bonds usually occur between metal and nonmetal ions. For example, sodium (Na), a metal, and chloride (Cl), a nonmetal, form an ionic bond to make NaCl.
What type of flower structures do you see in a ovary in a flower
Answer:
The ovary contains ovules
Explanation:
why does it make sense for the valence electrons to increase going across a period?
During an experiment, a canister filled with hot water was added to a beaker filled with cold water. In which direction did the heat energy move?
A) The heat energy moved from the hot water of the canister into the cold water of the beaker.
B) The heat energy moved from the cold water of the beaker into the hot water of the canister.
Equal amounts of heat energy from each container moved in both directions
D) No heat energy moved, as it all remained in the canister of hot water.
Answer:
A
Explanation:
As per the concept of thermal energy, heat energy will be moved from hot water of canister to cold water of beaker as heat flows from point at high temperature to point at lower temperature.
What is thermal energy?Thermal energy is defined as a type of energy which is contained within a system which is responsible for temperature rise.Heat is a type of thermal energy.It is concerned with the first law of thermodynamics.
Thermal energy arises from friction and drag.It includes the internal energy or enthalpy of a body of matter and radiation.It is related to internal energy and heat .It arises when a substance whose molecules or atoms are vibrating faster.
These vibrating molecules and atoms collide and as a result of which heat is generated in a substance , more the collision of particles , higher is the thermal energy.
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what kind of molecule is a polymer??
Answer:
macromolecules
Explanation:
Polymer is composed of molecules called macromolecules that have multiple of simpler chemical units called monomers.
"Which type of reaction is used to measure immune complex formation almost immediately after reagent has been added by the amount of light scattered at a particular angle"
Answer:
nephelometry
Explanation:
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what is the maximum wavelength of light that can ionize hydrogen in its ground state?
Answer: 123×10−7m.
Explanation:
define pure substance
What is friction? A _______ between an object and the _______ it's moving over.
Answer:
A force between an object and the surface it's moving over.
Explanation:
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if the student finds the weight of the sodium chloride to be 28.5g,calculate the number of particles.(Na=23,Cl=35.5)
Answer:
2.93×10^23
Explanation:
molecular formula of NaCl is 58.5
58.5gof NaCl=6.023×10^23
28.5g of NaCl= 6.023×10^23÷58.5×28.5
= 2.93×10^23
hi. can you help me
column table in two words?
Answer:
a table is a grid of rows and columns that intersect to form cells
Explanation:
A species acts as a(n) _____ agent if it gains electrons in a half-reaction. Conversely, it could potentially act as a(n) _____ agent if it loses electrons in a half-reaction.
A species acts as an oxidizing agent if it gains electrons in a half-reaction. Conversely, it could potentially act as a reducing agent if it loses electrons in a half-reaction.
REDOX REACTION:
Redox (oxidation-reduction) reaction is a type of reaction that involves the loss and gain of electrons by substances involved. Redox reaction involves a reducing agent and an oxidizing agent. Oxidizing agent gains electrons in a redox reaction while reducing agent loses electrons. Oxidizing agent gets reduced in the process while reducing agent gets oxidized.Learn more about redox reaction at: https://brainly.com/question/13293425?referrer=searchResults
what is the answer to this:magnesium+oxygen
Answer:
magnesium oxide
Explanation:
A significant amount of methane (CH4) is trapped underground or under marine sediments as Select one: a. methane hydrates. b. liquid methane. c. inorganic carbon. d. natural gas.
Methane is found under the ground or under marine sediments as natural gas which is mined along with crude oil.
Methane is an alkane and has the formula CH4. It is most commonly used as fuel. Methane is the gas that has been renowned as being responsible for explosion in coal mines.
Methane is found under the ground as natural gas which is mined along with crude oil. Large deposit of natural gas is found in many countries in Asia, Africa and the middle east.
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which element is in period 2 and group 6
Which process requires water to gain heat energy from th
environment?
O condensation
O evaporation
infiltration
precipitation
Answer:
Evaporation, please mark me Brainliest
Metals usually lose electrons
and become
Answer:
A positive ion
Explanation:
when an atom losses an ion it become positive while when an atom gains an atom it becomes negative
Write the balanced COMPLETE ionic equation for the reaction when Na₂CO₃ and AgNO₃ are mixed in aqueous solution. If no reaction occurs, simply write only NR.
Answer:
see explanation
Explanation:
Write the balanced COMPLETE ionic equation for the reaction when Na₂CO₃ and AgNO₃ are mixed in aqueous solution. If no reaction occurs, simply write only NR.
Ag (+1) + NO3(-1) + 2 Na(+1) + Co3 (-2)--> Ag2CO3 (s) + 2 Na (+1) + 2NO3(-1)
how many ounces in a small can of crushed pineapple?
Answer:
Hey mate.....
Explanation:
This is ur answer.....
Crushed Pineapple in 100% Pineapple Juice 8 oz can.Hope it helps!
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life situation scenario that portrays the modernization and professionalism of the Philippine National Police Organization as per discussed under RA 6975.
Answer:
members shall perform their duties with integrity, intelligence and competence in the application of specialized skill and technical knowledge with excellence and expertise.
Explanation:
any members on duty should be wiling and ready to help at all times
pls help my test is tomorrow
2Na + Cl(small 2) = 2NaCl
describe the reaction of sodium in terms of the names the substances and the number of atoms involved
What is defined as the amount of water vapor in the air?
Answer:
It is called absolute humidity.
Explanation:
In the Periodic Table below, shade all the elements for which the neutral atom has an outer electron configuration of ms1 nd10, where n and m are integers, and m= n+1.
Answer:
Cu, Ag, Au, Rg
Explanation:
The periodic table is an arrangement of elements in rows and columns. The elements with outer electron configuration of ms1 nd10 are Cu, Ag, Au, Rg.
The periodic tableThe periodic table is an arrangement of elements in rows and columns. The rows are called periods while the columns are called groups.
Now we know that the group that is referred to here has an outer electron configuration of ms1 nd10. This corresponds to the elements Cu, Ag, Au, Rg.
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Explain The element lithium has two common isotopes: Li–6 and Li–7 If the average atomic mass of lithium is 6.94004 u, determine its percent isotopic step by step please urgently
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%