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. What is the mass, in grams, of a sample of 7.83 × 1024 atoms of helium (He)?

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. What is the mass, in grams, of a sample of 7.83 × 1024 atoms of helium (He)?

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WILL GIVE BRAINLIEST PLEASE HELP! Please select the word from the list that best fits the definition stage in a star’s evolution formed as the core of a main sequence star uses up its helium and the outer layers escape into space

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Answered by answersmine AT 22/10/2019 – 03:07 AM


sorry I’m late
white dwarf is late stage in the life cycle of a comparatively low-mass main sequence star; formed when its core depletes its helium and its outer layers escape into space, leaving behind a hot, dense core. so the that would be the most reasonable answer thanks for posting, hope i helped

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What is the electron configuration for helium (He)? 1s1 1s2 1s22s1 1s22s2

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25) Answer is: less metallic and more nonmetallic.

Electronegativity increases from left to right across a period, atoms have tendency to attract electrons.

Electronegativity (χ) is a property that describes the tendency of an atom to attract a shared pair of electrons.

26) Answer is: radioisotope.

Radioisotope has an unstable atomic nucleus and emit energy and particles when it changes to a more stable form.

Francium (Fr) is element with atomic number 87 (87 protons and 87 electrons).

27) Answer is: boils.

Boiling is the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere.

The Celsius scale was based on 0°C for the freezing point of water and 100°C for the boiling point of water at 1 atm pressure.

28) Answer is: endothermic.

There are two types of reaction:  

1) endothermic reaction (chemical reaction that absorbs more energy than it releases, ΔH>0).

2) exothermic reaction (chemical reaction that releases more energy than it absorbs).  

For example, the breakdown of ozone is an endothermic process. Ozone has lower energy than molecular oxygen (O₂) and oxygen atom, so ozone need energy to break bond between oxygen atoms.  

29) Answer is: kinetic.

The average kinetic energy of molecules depends on the temperature.  

As temperature increases, molecules gain more energy from surrounding and move faster.  

Kinetic energy (standard unit is the joule J) depends on speed of the molecule.  

Solid gains kinetic energy to become a liquid and then becomes a gas.

30) Answer is: alpha particles.

This was famous Rutherford’s Gold Foil Experiment: he bombarded thin foil of gold with positive alpha particles.

Rutherford observed the deflection of alpha particles on the photographic film.  

Alpha particles are helium atom particles, consist of two protons and two neutrons.  

According to Rutherford model of the atom: atoms have their charge concentrated in a very small nucleus.  

31) Answer is: highest.

For example, calcium oxide.

Calcium oxide (CaO) has ionic bonds between calcium cations (Ca²⁺) and oxygen anions (O²⁻).

Because it has strong ionic bonds, it has high melting point (around 2600°C).

Ionic bond is the electrostatic attraction between oppositely charged ions (cations and anions).

32) Answer is: a scientific model.

A scientific model is a representation of an idea, an object, a process or a system that is used to describe and explain phenomena that cannot be experienced directly.

33) Answer is: the superscript is mass number and the subscript is atomic number.

Atomic number(Z) is the number of protons, which is characteristic of a chemical element..

Mass number (A) is the total number of protons and neutrons in a nucleus.

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25. From left to right across a period in the periodic table, elements become less ___________ and more ______________ in their properties. 26. Francium has 36 isotopes, but only francium-223 occurs in nature. Francium-223 spontaneously emits particles and energy, so francium-223 is a(an) _____________ of francium. 27. At sea level, water ______________ at 100°C. 28. Cooking requires continuous addition of energy to the chemical reactions that are taking place. The chemical reactions involved in cooking can be described as __________________. 29. The ________________ theory of matter states that all particles of matter are in constant motion. 30. In Rutherford’s experiments, some of the _______________ aimed at gold atoms bounced back, suggesting that a solid mass was at the center of the atom. 31. You are given the melting points of three unknown substances and are asked to predict which one is an ionic compound. You would select the compound with the ________________ melting point. 32. A flight simulator that helps astronauts prepare for a shuttle launch is an example of a(an) __________________. 33. In the symbol ■([email protected]) He, the superscript 4 is the _________________ for helium, and the subscript 2 is the ___________________ for helium.

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25) Answer is: less metallic and more nonmetallic.

Electronegativity increases from left to right across a period, atoms have tendency to attract electrons.

Electronegativity (χ) is a property that describes the tendency of an atom to attract a shared pair of electrons.

26) Answer is: radioisotope.

Radioisotope has an unstable atomic nucleus and emit energy and particles when it changes to a more stable form.

Francium (Fr) is element with atomic number 87 (87 protons and 87 electrons).

27) Answer is: boils.

Boiling is the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere.

The Celsius scale was based on 0°C for the freezing point of water and 100°C for the boiling point of water at 1 atm pressure.

28) Answer is: endothermic.

There are two types of reaction:  

1) endothermic reaction (chemical reaction that absorbs more energy than it releases, ΔH>0).

2) exothermic reaction (chemical reaction that releases more energy than it absorbs).  

For example, the breakdown of ozone is an endothermic process. Ozone has lower energy than molecular oxygen (O₂) and oxygen atom, so ozone need energy to break bond between oxygen atoms.  

29) Answer is: kinetic.

The average kinetic energy of molecules depends on the temperature.  

As temperature increases, molecules gain more energy from surrounding and move faster.  

Kinetic energy (standard unit is the joule J) depends on speed of the molecule.  

Solid gains kinetic energy to become a liquid and then becomes a gas.

30) Answer is: alpha particles.

This was famous Rutherford’s Gold Foil Experiment: he bombarded thin foil of gold with positive alpha particles.

Rutherford observed the deflection of alpha particles on the photographic film.  

Alpha particles are helium atom particles, consist of two protons and two neutrons.  

According to Rutherford model of the atom: atoms have their charge concentrated in a very small nucleus.  

31) Answer is: highest.

For example, calcium oxide.

Calcium oxide (CaO) has ionic bonds between calcium cations (Ca²⁺) and oxygen anions (O²⁻).

Because it has strong ionic bonds, it has high melting point (around 2600°C).

Ionic bond is the electrostatic attraction between oppositely charged ions (cations and anions).

32) Answer is: a scientific model.

A scientific model is a representation of an idea, an object, a process or a system that is used to describe and explain phenomena that cannot be experienced directly.

33) Answer is: the superscript is mass number and the subscript is atomic number.

Atomic number(Z) is the number of protons, which is characteristic of a chemical element..

Mass number (A) is the total number of protons and neutrons in a nucleus.

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How can a sample of uranium-235 that has critical mass be induced to react? it must be spilt with a laser. it must be fused to a helium nucleus. it must be bombarded with neutrons. it must be shot with light speed electrons?

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The unknown of this problem is the experimental percent of water in the compound in order to remove the water of hydrogen, given the following:

Mass of crucible, cover and contents before heating                               23.54 g
Mass of empty crucible and cover                                                            18.82 g
Mass of crucible, cover, and contents after heating to constant mass     20.94 g

In order to get the answer, determine the following:

Mass of hydrated salt used                          = 23.54 g – 18.82 g = 4.72 g
Mass of dehydrated salt after heating          = 20.94 g – 18.82 g = 2.12 g
Mass of water liberated from salt                 = 4.72 g – 2.12 g = 2.60 g

Then solve the percent of water in the hydrated salt by:

% water = (mass of water / mass of hydrated salt) x 100
% water = 2.60 g / 4.72 g x 100
% water = 55.08 % in the compound 

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Which type of radiation particle, emitted from a nuclear reaction, is most similar to a helium nucleus? alpha beta gamma isotope

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Which type of radiation particle, emitted from a nuclear reaction, is most similar to a helium nucleus? alpha beta gamma isotope

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A helium balloon contains 0.54 g of helium. given the molecular weight of helium is 4.0 g/mol, how many moles of helium does it contain?

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25) Answer is: less metallic and more nonmetallic.

Electronegativity increases from left to right across a period, atoms have tendency to attract electrons.

Electronegativity (χ) is a property that describes the tendency of an atom to attract a shared pair of electrons.

26) Answer is: radioisotope.

Radioisotope has an unstable atomic nucleus and emit energy and particles when it changes to a more stable form.

Francium (Fr) is element with atomic number 87 (87 protons and 87 electrons).

27) Answer is: boils.

Boiling is the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere.

The Celsius scale was based on 0°C for the freezing point of water and 100°C for the boiling point of water at 1 atm pressure.

28) Answer is: endothermic.

There are two types of reaction:  

1) endothermic reaction (chemical reaction that absorbs more energy than it releases, ΔH>0).

2) exothermic reaction (chemical reaction that releases more energy than it absorbs).  

For example, the breakdown of ozone is an endothermic process. Ozone has lower energy than molecular oxygen (O₂) and oxygen atom, so ozone need energy to break bond between oxygen atoms.  

29) Answer is: kinetic.

The average kinetic energy of molecules depends on the temperature.  

As temperature increases, molecules gain more energy from surrounding and move faster.  

Kinetic energy (standard unit is the joule J) depends on speed of the molecule.  

Solid gains kinetic energy to become a liquid and then becomes a gas.

30) Answer is: alpha particles.

This was famous Rutherford’s Gold Foil Experiment: he bombarded thin foil of gold with positive alpha particles.

Rutherford observed the deflection of alpha particles on the photographic film.  

Alpha particles are helium atom particles, consist of two protons and two neutrons.  

According to Rutherford model of the atom: atoms have their charge concentrated in a very small nucleus.  

31) Answer is: highest.

For example, calcium oxide.

Calcium oxide (CaO) has ionic bonds between calcium cations (Ca²⁺) and oxygen anions (O²⁻).

Because it has strong ionic bonds, it has high melting point (around 2600°C).

Ionic bond is the electrostatic attraction between oppositely charged ions (cations and anions).

32) Answer is: a scientific model.

A scientific model is a representation of an idea, an object, a process or a system that is used to describe and explain phenomena that cannot be experienced directly.

33) Answer is: the superscript is mass number and the subscript is atomic number.

Atomic number(Z) is the number of protons, which is characteristic of a chemical element..

Mass number (A) is the total number of protons and neutrons in a nucleus.

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If you send a sound wave of the same wavelength (λ = 2.00 m) through air, helium, and carbon dioxide, describe how the pitch of the sound will compare through each medium.

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My answer –


Electrical pressure, called “electro-motive force” (EMF), is what causes current
to flow in an electrical circuit. EMF is measured in volts. Pressure and the quantity of electricity transmitted can be considered analogous to pressure and quantity of water flowing in pipes: the longer the distance, the higher is the flow of water (called the “flow of electrical charge, which is also known as the “electric current”). That is why, for long distance transmission, high pressure (voltage for electricity) is required, failing which, the current – and therefore the power – will not reach the intended destination. Instead, it will be lost (also called “dissipate”) along the way. We can think of electrical
 
current as the quantity of electricity which will be drawn from the pipeline

cables for electricity) at the pressure (= voltage) required.

P.S

Happy to help you have an AWESOME!!! day ^-^

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