Lab: Ionic and Covalent Bonds

Explanation:

When Henri Becquerel investigated the newly discovered X-rays in 1896, it led to studies of how uranium salts are affected by light. By accident, he discovered that uranium salts spontaneously emit a penetrating radiation that can be registered on a photographic plate.

Answer:

true

Explanation:

As mentioned above, the moon does not have the same composition as the Earth, and while some of the elements present on the moon are the same, this is likely because of the moon’s formation (the Giant-Impact Theory). In general, this different in composition means that the moon cannot have an atmosphere because it is not geologically active.

Heterogeneous, which means that they are not evenly combined.

Answer:Cats’ ability to land on their feet can be chalked up to the “righting reflex” that they possess:)

Explanation:

Answer:

Explanation:  Correct on Edg 2020/2021.

Answer:because they run out of energy when it is transferred and to other objects, or their kinetic energy

Explanation:

Answer:

The water in glass turns dark brown.

This is due to diffusion where the coffee molecules move from the region of their high concentration to a region of their lower concentration in water.

Answer:

The instant coffee acts as a solute when hot water (the solvent) is poured.  The instant coffee quickly dissolves and makes a solution.

Explanation:

Answer:

821.25gm

Explanation:

volume = 657

no of mole = 657/22.4

mass = no of mole * molecular mass

mass = 657/22.4*28

= 821.25gm

Answer:

Three types of chemical bonds are important in human physiology, because they hold together substances that are used by the body for critical aspects of homeostasis, signaling, and energy production, to name just a few important processes. These are ionic bonds, covalent bonds, and hydrogen bonds.

Explanation:

a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.

Answer:

Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products

Explanation:

Answer:

Hydrosulfuric acid will act as limiting reactant.

Explanation:

Given data:

Mass of iron(III) chloride = 3243.0 g

Mass of hydrosulfuric acid = 511.8 g

Limiting reactant = ?

Solution:

Chemical equation:

2FeCl₃ + 3H₂S       →       Fe₂S₃ + 6HCl

Number of moles of iron(III) chloride:

Number of moles = mass/molar mass

Number of moles = 3243.0 g/ 162.2 g/mol

Number of moles = 20 mol

Number of moles of hydrosulfuric acid:

Number of moles = mass/molar mass

Number of moles = 511.8 g/ 34.1 g/mol

Number of moles = 15 mol

Now we will compare the moles of both reactant with products

                      FeCl₃          :          Fe₂S₃

                       2                :            1

                      20               :          1/2 ×20 = 10

                      FeCl₃          :            HCl

                       2                :              6

                      20               :          6/2 ×20 = 60

                      H₂S             :          Fe₂S₃

                       3                :            1

                      15               :          1/3 ×15 = 5

                      H₂S            :            HCl

                       3                :              6

                      15                :          6/3 ×15 = 30

Hydrosulfuric acid producing less number of moles of product thus, it will act as limiting reactant.

Answer:

Thus, to calculate the stoichiometry by mass, the number of molecules required for each reactant is expressed in moles and multiplied by the molar mass of each to give the mass of each reactant per mole of reaction. The mass ratios can be calculated by dividing each by the total in the whole reaction.

Explanation: Stoichiometry is the field of chemistry that is concerned with the relative quantities of reactants and products in chemical reactions. For any balanced chemical reaction, whole numbers (coefficients) are used to show the quantities (generally in moles ) of both the reactants and products.

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, lead has the highest mass. 141.05gram of MgO are in 3.500 moles.

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. 141.05gram is the mass of  MgO.

Mathematically, the molar mass, mole and given mass can be related as

Mole of MgO =given mass of  MgO ÷ molar mass of  MgO

Molar mass of MgO= 40.30 g/mol

Mole of MgO= 3.500 moles

substituting the values, we get

3.500 moles = mass of MgO÷ 40.30 g/mol

Mass of MgO=141.05gram

Therefore, 141.05gram of MgO are in 3.500 moles.

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Answer:

the answer maybe is 61.5 years (please check with others) tq

Explanation:

40/2=20

20/2=10

10/2=5

5/2=2.5

2.5/2=1.25

so one half life is 12.3 years

then 12.3 ×5 =61 .5

(why 5 ? because it decay 5 times to get 1.25 from 20)

Answer: D. An increase in entropy

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from  an disordered arrangement to an ordered arrangement, the entropy is said to increase and vice versa.

For a reaction to be spontaneous, the enthalpy of the solution must decrease and the entropy must increase.

To overcome a positive enthalpy of solution and allow a solid  solute to dissolve in water, an increase in entropy would make the reaction spontaneous as the system would move to a more disordered state.

Answer: the 3 one

Explanation: i just know

Answer:

how systems violate the law of the second law of thermodynamics

Explanation:

i had to take this quiz it is the right answer..

Answer:

Cellular respiration

Answer:

cellular respiration

Explanation:

Answer:

Albedo

Explanation:

Usually when we talk about uneven heating of the Earth's surface we are discussing convection. The uneven heating results in some of the atmosphere to be warmer than other parts and changes in volume and pressure which result in updrafts and can cause thunderstorms and other violent weather. The cause of this is the reflectiveness of the surface of the Earth at that point (the albedo) and the angle that the sun's rays strike it at. A field covered with snow and ice is going to be much more reflective than a black top asphalt parking lot. As such the parking lot absorbs much more shortwave radiation from the sun and gets much warmer.

The uneven heating of Earth caused by the Sun craetes the difference in the atmosphere pressure and the volume of gasses present in atmosphere.

The uneven heating in the atmosphere disturbs the climatic conditions as there are some areas which are cold and some are hot then before and also changes the volume and pressure.

The change in the volume and the pressure results in the flow of the upward flow of the current air which is the main cause of thunder storm and some other climatic disaster can also happen.

Therefore,  uneven heating of Earth caused by the Sun craetes the difference in the atmosphere pressure and the volume of gasses present in atmosphere.

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Answer:

Magnesium

Explanation:

Magnesium is in group 2 of the periodic table. The group in which an element is found in tells us the number of valence eletrons it has.

HOPE THIS HELPED

Among the given elements, the element that have two valence electrons is Magnesium. The correct answer is option B.

Valence electrons are the electrons that are present in the outermost shell of an atom that are involved in chemical bonding. The number of valence electrons an atom has is determined by the group number it belongs to on the periodic table.

Magnesium belongs to group 2A on the periodic table, which means it has two valence electrons.

Carbon belongs to group 4A and has four valence electrons, while Fluorine belongs to group 7A and has seven valence electrons. And Sodium belongs to group 1A and has one valence electron.

Therefore, option B. Magnesium is the elements that have two valence electrons.

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Answer:

5446.8 J

Explanation:

From the question given above, the following data were obtained:

Mass (M) = 50 g

Initial temperature (T₁) = 70 °C

Final temperature (T₂) = 192.4 °C

Specific heat capacity (C) = 0.89 J/gºC

Heat (Q) required =?

Next, we shall determine the change in the temperature. This can be obtained as follow:

Initial temperature (T₁) = 70 °C

Final temperature (T₂) = 192.4 °C

Change in temperature (ΔT) =?

ΔT = T₂ – T₁

ΔT = 192.4 – 70

ΔT = 122.4 °C

Finally, we shall determine the heat required to heat up the block of aluminum as follow:

Mass (M) = 50 g

Specific heat capacity (C) = 0.89 J/gºC

Change in temperature (ΔT) = 122.4 °C

Heat (Q) required =?

Q = MCΔT

Q = 50 × 0.89 × 122.4

Q = 5446.8 J

Thus, the heat required to heat up the block of aluminum is 5446.8 J

Answer:

when you burn wood in a campfire, chemical energy is converted to heat and light energy.

Explanation :

When wood is burned stored potential energy ( in the form of chemical energy ) in the log is released due to heating by other excited atoms . This process is called combustion and requires presence of oxygen. So,  combustion can be defined as a process which changes chemical energy into kinetic energy in the form of heat.  In case of combustion  an organic say wood in this case combines with oxygen present in the atmosphere to give off carbon dioxide, water and energy in the form of heat and light .    

Answer:

9 g/ml

Explanation:

5 + 3.3 = 8.5

But you should use sig figs.

5 has no tenths, hundredths, and etc.

Therefore the 8.5 rounds up to 9

So the answer is 9.

Answer:

It has mass but no charge.

Explanation:

The question asks to describe ONE of the subatomic particles that could be found at location X in the model, so you should think of protons and neutrons. Now all of the answers do NOT describe a proton, but the first answer describes a neutron. Neutrons have mass but no charge. Why? The neutron has two down quarks and one up quark, down quarks, have a charge of -1/3, and up quarks have a charge of +2/3. Doing the math, you'd see that (-1/3)2+2/3 is equal to a neutral charge. So a neutron WILL have a mass, but will NOT have a charge, as they are used to hold the nucleus together.

Answer:

the last one

Explanation:

Answer:

satellite

Explanation:

found it on the internet

The correct answer is Radar

Answer:

A) attract

Explanation:

hope it helps you

To see the number of atoms of an element in a given molecule we need to multiply stoichiometry to the number that is written on the foot of the element that is stoichiometry. Therefore, the correct option is option A.

Atom is the smallest particle of any element, molecule or compound. Atom can not be further divided. Atoms contains nucleus in its center and electron that revolve around the atom in fixed orbit.

In the nucleus, proton and neutron are present. Electron has -1 charge while proton has +1 charge. Neutron is neutral that is it has no charge. So overall the charge of nucleus is due to only proton, not by neutron. Just like the N and S poles on bar magnets, electrons and protons attract each other.

Therefore,  the correct option is option A.

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by rounding them to the neerest 10

Answer:

This accepting atom will then become an anion. The anion has more electrons than protons. This means that some of the electrons will not be canceled out, giving the atom an overall negative charge.

If an object has more protons than electrons, then the net charge on the object is positive. If there are more electrons than protons, then the net charge on the object is negative. If there are equal numbers of protons and electrons, then the object is electrically neutral.

Explanation:

Answer:

30.11 × 10²³ atoms

Explanation:

Given data:

Number of moles of gold = 5 mol

Number of atoms = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.  The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

5 mol × 6.022 × 10²³ atoms /1 mol

30.11 × 10²³ atoms