What mass of aluminium is needed to react with 640g of iron oxide

Answer:

The ovary contains ovules

Explanation:

Answer:

macromolecules

Explanation:

Polymer is composed of molecules called macromolecules that have multiple of simpler chemical units called monomers.

Answer:

magnesium oxide

Explanation:

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.

A. ionic (donates an electron to the other atom in the bond)

B. covalent (electrons are shared equally)

C. polar (unequal electronegativity)

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Answer: Particle F is an anion, and particle E is a cation

Explanation:

A particle is a cation if it has more protons  than  electrons.

A particle is an anion if it has more electrons than protons.

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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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Answer:

1.22gram of hydrogen is needed to react

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore,  0.40 g mass of hydrogen is needed to react with 32 g of copper oxide.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Mathematically,

CuO + H[tex]_2[/tex]→ Cu + H[tex]_2[/tex]O

mole of copper oxide=  32 /79.54

                                    =0.40 mole

The mole ratio between copper oxide and hydrogen is 1:1

mole of hydrogen= 0.40 mole

mass of hydrogen = 0.40 mole×1g/mol

                              = 0.40 g

Therefore, 0.40 g mass of hydrogen is needed to react with 32 g of copper oxide.

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Answer:

element

Explanation:

hope this helps

Explanation:

Elements are pure substances that cannot be broken down into simpler substances by ordinary chemical means.

Answer:

731.5j.

Explanation:

Basic Formula : Q = mcT.

Q - Heat gained or lost.

m - mass of the given substance.

c - specific heat capacity.

T - Change in temperature ( it often has a delta(triangle) before it.

so now we are directly asked to find the heat.

Q = mcT

m= 5g

c = 4.18

but T = 35k which means 35 kelvin.

why? because you will need to convert the two given initial and final temperatures inorder to cancel the unit kelvin out from the formula above. the target is simply to make the unit J - joule be left alone.

now We convert celsius temperature to kelvin by adding a constant of 273.15 approximately 273.

therefore - Tk = Tc + 273

which will be equivalent to 295k for the initial temperature and 330k for the final.

now granted...keep in mind to use the CHANGE in temperature which is the difference of the 2 kelvin temperatures we just converted

so T = 330k - 295k = 35k

then just substitute everything in the very 1st formula i stated above.

Q = mcT = 5 x 4.18 x 35 = 731.5 J

peace to you.

Answer:

15.1 grams

Explanation:

Answer:

I did some research and found some things here, its another sight sort of like brainly.  Hopefully this helps!

Explanation:

https://socratic.org/questions/how-many-grams-of-potassium-chloride-are-produced-if-25-0g-of-potassium-chlorate

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

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:

Answer:

Melted ionic compounds

Explanation:

This is because the ions have dissociated and for electricity to pass through a substance it is important that the substance must have ions present in it.

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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Answer:

0.143kg/m^3

Explanation:

density= mass / volume

Answer:

1/7 kg/cubic metres

Explanation:

Here, Density=mass /volume

=6/42

=1/7 kg/cubic metres.

Answer:

A force between an object and the surface it's moving over.

Explanation:

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Answer:

D. weight

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If a solid object is taken from Earth far into space, which of the following measurements of the object will change the most?

A. density

B. mass

C. volume

D. weight

option D. weight

Because the gravity of the planet/object changes, the weight of the object changes when you move it away from the earth or place it on another planet.

However, the mass of the object remains the same regardless of whether it is on Earth or outer space.

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

Answer:

atomic watch

Explanation:

it is used for the measurement of time.

After beginning the experiment with a saturated solution, then increasing the heat, we will be left with an unsaturated solution.

To obtain the saturated solution, we must dissolve sugar in the water. We can say that the solution has become saturated when the solution is no longer able to dissolve more sugar. It has reached its capacity for the solute that it can dissolve in these conditions.

However, the temperature of a solution has an effect on the dissolving limit of the solution. That is, when a solution is heated it becomes able to dissolve more solute. Therefore, if we were to heat a saturated solution, it will be able to dissolve more solute and therefore will no longer be at its limit, meaning it is no longer a saturated solution. It has become unsaturated.

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Answer: The four forces acting on an aircraft in straight-and-level, unaccelerated flight are thrust, drag, lift, and weight.

Explanation:

The liquid did not chemically bond after 3 days, therefor it is a mixture.

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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%

Answer:

CO2 carbon dioxide emissions

H20 mental breakdown

02 is form of a kind

answer is acid + alkaline equal to salt and water