A certain ore is 37.3 % nickel by mass. How many kilograms of this ore would you need to dig up to have 65.0 g of nickel

Answer:

hope this help

Explanation:

change: volume of solid , volume of liquid , the volume of gases

not change: the shape of solid , the shape of liquid , the shape of gases

Answer:

hope it helps you

Explanation:

i think is d

true  becouse i sed so                                            

Answer:

kinetic energy I think so

The form of energy molecules have at the molecular level is Kinetic energy.

Kinetic energy is defined as the energy possessed by a body as a result of its motion or movement.

Molecules interact with one another through various movements that occur

within them. This happens to aid the formation of new substances in the

ecosystem. The three states of matter exhibit varying degree of movement

within its molecules.

The energy is usually in the form of chemical energy also and is the reason

why kinetic energy is the most suitable choice.

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Answer: Alloy

Explanation: gold is an alloy, or mixture of metals

Answer:

D. All living things provides heat and light on Earth.

Explanation:

its the sun that does that

Answer:

option d.

Explanation:

all living things provides heat and light on Earth.

Answer:

D. Oxidation

Explanation:

In an electrolytic cell, oxidation (the loss of electrons) takes place at the anode. At the cathode reduction takes place.

A mnemonic technique that could be used is that the process that starts with a vowel (Oxidation) takes place at the place that also starts with a vowel (Anode).

In the image shown above, there are 3 elements (option C).

Element is one of the simplest chemical substances that cannot be decomposed in a chemical reaction or by any chemical means and made up of atoms all having the same number of protons.

As stated above, all elements are made up of backbone structures called atoms. The atoms of an element are the same.

According to this question, an image is given showing atoms of different colors. Each atom with the same color belongs to a single element.

Since there are there colors, this means that there are three elements in the picture.

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Answer:

True

Explanation:

Answer:

36 electrons

Explanation:

The # of protons is always equal to the atomic number. In the case of Sr (Strontium), it is 38 protons.

The 2+ at the end means that it has a charge of +2, meaning that it LOST two electrons to become a cation with a full valence shell. So, 38 - 2 = 36 electrons

Answer:

38 protons 36 electrons 30 neutron because of 29 isotope

Answer:

N2H4 + 3O2 → 2NO2 + 2H2O

Explanation:

Answer:

The relationship is the "variation of vapour pressure with temperature" or " the effect of vapour pressure on the melting and boiling points in a phase"

Answer:

They are all mixture

Explanation:

last option

Answer:

[tex]PNCl_2[/tex]

Explanation:

Hello!

In this case, when determining empirical formulas by knowing the by-mass percent, we first must assume the percentages as masses so we can compute the moles of each element:

[tex]n_P=\frac{26.73g}{30.97g/mol}=0.863mol\\\\n_N=\frac{12.09g}{14.01g/mol}=0.863mol\\\\n_C_l=\frac{61.18g}{35.45g/mol}=1.726mol[/tex]

Now, for the determination of the subscript of each element in the empirical formula, we divide the moles by the fewest moles (P or N):

[tex]P=\frac{0.863mol}{0.863mol}=1\\\\N= \frac{0.863mol}{0.863mol}=1\\\\Cl=\frac{1.726mol}{0.863mol}2[/tex]

Thus, the empirical formula is:

[tex]PNCl_2[/tex]

Regards!

Answer: The possible molecular formula will be [tex]CO_2[/tex]

Explanation:

Mass of C= 27.3 g

Mass of O = 72.7 g

Step 1 : convert given masses into moles.

Moles of C =[tex]\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{27.3g}{12g/mole}=2.275moles[/tex]

Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{72.7g}{16g/mole}=4.544moles[/tex]

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C = [tex]\frac{2.275}{2.275}=1[/tex]

For O =[tex]\frac{4.544}{2.275}=2[/tex]

The ratio of C : O = 1: 2

Hence the empirical formula is [tex]CO_2[/tex]

The possible molecular formula will be=[tex]n\times CO_2[/tex]

Answer:

Explanation:

p-diaminobenzene is popularly known as p-phenylenediamine. It undergoes a condensation reaction with metal halides. As a white solid (p-diaminobenzene), it can be darkened by air oxidation. The reaction showing the condensation of p-phenylenediamine with (CoCl)₂ can be seen in the image attached below.

Answer:

5.44 moles of nitrogen required.

Explanation:

Given data:

Number of moles of NH₃ = 10.88 mol

Moles of N₂ required = ?

Solution:

Chemical equation:

N₂ +  3H₂         →       2NH₃

Now we will compare the moles nitrogen and hydrogen.

               NH₃          :           N₂

                 2             :           1

               10.88        :         1/2×10.88 = 5.44mol

5.44 moles of nitrogen required.

Answer:

[tex]4.86\times10^{-7}\ \text{m}[/tex]

Explanation:

R = Rydberg constant = [tex]1.09677583\times 10^7\ \text{m}^{-1}[/tex]

[tex]n_1[/tex] = Principal quantum number of an energy level = 2

[tex]n_2[/tex] = Principal quantum number of an energy level for the atomic electron transition = 4

Wavelength is given by the Rydberg formula

[tex]\lambda^{-1}=R\left(\dfrac{1}{n_1^2}-\dfrac{1}{n_2^2}\right)\\\Rightarrow \lambda^{-1}=1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\\\Rightarrow \lambda=\left(1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\right)^{-1}\\\Rightarrow \lambda=4.86\times10^{-7}\ \text{m}[/tex]

The wavelength of the light emitted is [tex]4.86\times10^{-7}\ \text{m}[/tex].

Identify the type of solid from the description. Select from the following choices: metallic solid, network solid, molecular solid, ionic solid, or amorphous solid. a. This solid is ductile and conducts electricity.b. This solid is not conductive and has a low melting point.

Answer:

See explanation

Explanation:

A is a Metallic Solid

Let us look again at the physical properties of metals;

Metals are

We can now see that both ductility and electrical conductivity are metallic properties.

B is a Molecular solid

Molecules are formed when atoms share electrons. In molecules, there are no free electrons hence molecules do not conduct electricity.

Secondly, molecules are held together in the solid state by weak dispersion forces hence molecular solids have a low melting point.

Answer:

C: The temperature of the substance increases as it sits in the beaker of water

Explanation:

This question was taken from a video where an attempt was made to investigate the changes in temperature when a substance undergoes change from it's solid phase to its liquid phase.

To do this, as seen in the video online, it shows a solid substance in a test tube being placed in a beaker of water.

From observation, the water in the beaker has a warmer temperature than the solid substance present in the test tube and this in turn makes the test tube gradually increase in temperature.

Thus, the solid substance will as well increase increase in temperature when it is placed in the beaker of water.

Answer:

B) 2

Explanation:

There are two significant figures in given measurement,

2, 0

Significant figures:

1= The given measurement have four significant figures 1534.

2= All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.

3= Leading zeros are not consider as a significant figures. e.g. 0.03 in this number only one significant figure present which is 3.

4= Zero between the non zero digits are consider significant like 107 consist of three significant figures.

5= The zeros at the right side e.g 2400 are also significant. There are four significant figures are present.

Answer:

Because the compound has a formula of M2O, the number of valence electrons of M should be 1. Therefore, (1) Group 1 is the correct answer because elements in group 1 have 1 valence electron.

Explanation:

Answer:

No; According to the IUPAC , it should be

Answer:

[tex]Mg(s)+2H^+(aq)\rightarrow Mg^{2+}(aq)+H_2(g)[/tex]

Explanation:

Hello!

In this case, since the writing of a net ionic equation first implies writing the complete molecular equation:

[tex]Mg(s)+2HCl(aq) \rightarrow MgCl_2(aq)+H_2(g)[/tex]

We can see that HCl and MgCl2 are ionized because they are aqueous, thus we write:

[tex]Mg(s)+2H^+(aq)+2Cl^-(aq) \rightarrow Mg^{2+}(aq)+2Cl^-(aq)+H_2(g)[/tex]

In such a way, we can cancel out the chloride ions as they are the spectator ones to obtain the net ionic one:

[tex]Mg(s)+2H^+(aq)\rightarrow Mg^{2+}(aq)+H_2(g)[/tex]

Best regards!

Answer:5 to the 7th power

Explanation:

Divided 7 and y then add 4

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 5.33×10²⁴moles are in 3.21×10²⁸ molecules of Nitrogen.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample.

Given number of molecules of nitrogen=3.21×10²⁸ atoms

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

mole of nitrogen=given number of atoms ÷ 6.022×10²³(Avogadro number)

Substituting the values

moles of nitrogen=3.21×10²⁸ ÷ 6.022×10²³

mole of nitrogen= 5.33×10²⁴moles

Therefore, 5.33×10²⁴moles are in 3.21×10²⁸ molecules of Nitrogen.

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