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Answer:

Oxygen

Explanation:

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

Number of electrons = 8

Number of protons = 8

Number of Neutrons = 8

Name of element =?

Next, we shall determine the atomic number of the element. This can be obtained as follow:

The atomic number of an element is simply defined as the number of protons in the atom of the element. Mathematically, it is expressed as:

Atomic number = proton number

From the question given above,

Number of protons = 8

Therefore,

Atomic number = 8

Comparing the atomic number of the element (i.e 8) with those in the periodic table, we can conclude that the element is oxygen since no two elements have the same atomic number.

Answer:regular variation in magnitude or position around a central point. Or movement back and forth at a regular speed

Explanation:

Answer:

movement back and forth at a regular speed

Explanation:

they be oscillatin

Answer:

4.46 °C

Explanation:

Step 1: Given and required data

Step 2: Calculate the temperature change

We will use the following expression.

Q = c × m × ΔT

ΔT = Q / c × m

ΔT = 4430 J / (4.186 J/g.°C) × 237 g

ΔT = 4.46 °C

The temperature change is 4.46 °C.

Answer:

• The closing of the frontier

Explanation:

• The closing of the frontier• The closing of the frontier• The closing of the frontier• The closing of the frontier• The closing of the frontier• The closing of the frontier• The closing of the frontier

Answer:

Aluminum can be extracted from bauxite ore.

Answer:

11x³ – 2x² + 3x + 11

Explanation:

From the question given above:

We are to find the sum of:

4x³ + 2x² – 4x + 3 and 7x³ – 4x² + 7x + 8

To add the above polynomials together we must recognise that we can only add like terms together. The sum of the above polynomials can be obtained as follow:

. 4x³ + 2x² – 4x + 3

+ 7x³ – 4x² + 7x + 8

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

= 11x³ – 2x² + 3x + 11

Thus, the sum of 4x³ + 2x² – 4x + 3 and 7x³ – 4x² + 7x + 8 is 11x³ – 2x² + 3x + 11

Answer:

Potential energy = mass(velocity)

Explanation:

It is the formula used to explain how to find the answer for potential energy

Answer:

Ethanol.

Explanation:

Hello!

In this case, since the Fischer esterification stand for the organic acid-base reactions, we infer that the alcohol is related to the -yl part on the name (ethyl propanoate) as the alcohol is likely to lose the -OH and provide a carbocation for the carboxyl group of the carboxylic acid.

In such a way, since the -yl part is given as ethyl, we infer the used alcohol is ethanol:

[tex]CH_3-CH_2-OH[/tex]

Best regards!

collision theory

Explanation:

Collision theory, theory used to predict the rates of chemical reactions, particularly for gases. The collision theory is based on the assumption that for a reaction to occur it is necessary for the reacting species (atoms or molecules) to come together or collide with one another.

Answer:

1.66x10⁶kJ of energy are produced

Explanation:

...Produces 45kJ... Has a density of 0.77g/mL... By burning 48L of gasoline...

To solve this question we need to calculate the mass in grams of gasoline in 48L using its density.

With the mass and knowing 1gram produces 45kJ of energy we can find the energy produced by burning 48L of gasoline, thus:

mL of gasoline:

48L * (1000mL / 1L) = 48000mL of gasoline

g of gasoline:

48000mL * (0.77g/mL) = 36960g of gasoline

Energy produced:

36960g of gasoline * (45kJ / g) =

Answer:

0.288g KBT can be dissolved

Explanation:

The dissolution of KBT produce the dissociation in K⁺ and BT⁻ ions as follows:

KBT(s) → K+(aq) + BT-(aq) Ksp = 3.8×10-4

Where Ksp is defined as:

Ksp = 3.8x10⁻⁴ = [K⁺][BT⁻]

Thus, we need to find the concentration of KBT that can be dissolved = [K⁺] = [BT⁻]:

3.8x10⁻⁴ = [K⁺][BT⁻]

3.8x10⁻⁴ = [KBT][KBT]

3.8x10⁻⁴ = [KBT]²

0.01949M = [KBT]

In 280mL = 0.280L, the moles of KBT that can be dissolved are:

0.01949mol / L * 0.280L =

5.458x10⁻³ moles of KBT. In grams (Using molar mass):

5.458x10⁻³ moles of KBT * (188.2g/mol) =

Answer:

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\[/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{7 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{7}{6.02} \\ = 1.162790....[/tex]

We have the final answer as

Hope this helps you

Answer:

100 POINTS! (50 split up) PLSSSSSSSSSS HELP!!! I REALLY NEED IT SO MUCH :( I PROMICE TO GIVE BRAINLIEST AND FIVE STARS AND A THANKS! 6TH GRADE SCIENCE! i used all my points for this!

You measure the mass of an apple using a balance. You get these three measurements:

Trial 1: 167.0 g

Trial 2: 166.9 g

Trial 3: 167.2 g

You know that the true mass of the apple is 172 g. Describe your results in terms of precision and accuracy. Explain your answer in a paragraph for the best grade.

Explanation:

Relative humidity is the percentage of what it can hold. Humidity is the measure of the amount of water vapor it can hold.

hope this helps ^^

Answer:

Nonmetals

Explanation:

Nonmetals typically lacks the metallic bonding which allows substances to exhibit metallic properties that confers special properties on them.

Nonmetals lacks these properties but metalloids are able to show some of the properties under certain and special conditions.

Answer:

icicle becausit sounds right

Explanation:

icicles because it sounds right

Answer:

0.0041 mol

Explanation:

Given data:

Number of formula units = 2.45 × 10²¹ formula units

Number of moles = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions ,formula units 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 formula units

2.45 × 10²¹ formula units × 1 mol / 6.022 × 10²³ formula units

0.41 × 10⁻² mol

0.0041 mol

Answer:

ΔH = -29.78 KJ/mol

Explanation:

To calculate the Standard enthalpy of change for this reaction, we need to use the following expression:

ΔH = ΔHf(products) - ΔHf(reactants)   (1)

Now, the standard heat of formation can be found in different handbooks or websites. I manage to find these for the compounds of the reaction:

ΔHf Ca(OH)₂ = -1002.82 KJ/mol

ΔHf HCl = -167.4 KJ/mol

ΔHf CaCl₂ = -795.8 KJ/mol

ΔHf  H₂O = -285.8 KJ/mol

With these values, we can calculate the enthalpy change of the reaction using (1). Let's calculate first the individual values of the products and reactants and then, we can use (1):

Reaction: Ca(OH)₂ + 2HCl ---------> CaCl₂ + 2H₂O

ΔHf (products) = ΔHf CaCl₂ + ΔHf H₂O

ΔHf (products) = (-795.8) + 2(-285.8)

ΔHf (products) = -1367.4 KJ/mol

Keep in mind that if the compound has a coefficient that balances the reaction, you need to multiply that number by the standard heat. Let's calculate reactants:

ΔHf (reactants) = ΔHf Ca(OH)₂ + ΔHf HCl

ΔHf (reactants) = (-1002.82) + 2(-167.4)

ΔHf (reactants) = -1337.62 KJ/mol

Finally using expression (1) we have:

ΔH = (-1367.4) - (-1337.22)

Answer:

d = 1.91 g/cm³

d = 1.91 g/mL

Explanation:

Given data:

Mass of cheese = 67 g

Volume of cheese = 35 cm³

Density of cheese = ?

Solution:

Formula:

d = m/v

by putting values,

d = 67 g/ 35 cm³

d = 1.91 g/cm³

1cm³ = 1mL

d = 1.91 g/mL

Answer:

There are 4 oxygen and 1 sulfur.

Explanation:

Calcium sulfate is made up of 1 calcium, 1 sulfur and 4 oxygen.

Answer:

0.00212 kgs

Explanation:

one gram is equal to 0.001 kilograms

The volume of avocado here is 250 ml as per the given data i.e., mass of 215 g and a density of 0.86 g/mL.

The density of an artifact is delineated as its mass divided by the volume. Density is commonly expressed in grams per cubic centimeter.

The grams are a unit of mass and indeed cubic centimeters are a unit of volume. A box with more particles will be denser than a box with fewer particles.

The density of a solid, liquid, or gas illustrates how closely packed the particles can be. The amount of mass per unit volume is defined as density.

Density is defined as d = M/V, where d is density, M is mass, and V is volume. Density is commonly measured in grams per cubic centimetre.

We know that,

Density = mass/volume.

Volume = mass/density.

Here, it is given that

Density = 0.86 g/mL.

Mass = 215 g.

Volume = 215/0.86 mL.

Volume = 250 mL.

Thus, the answer is 250 mL.

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Answer:

The most reactive metal elements is Group 1.

Answer:

12 moles of H₂SO₄

Explanation:

The reaction equation is given as;

          3H₂SO₄  +  2Fe⁻  →  Fe₂(SO₄)₃  +  3H₂

From the balanced reaction equation:

    Number of moles of Fe = 8moles  

So;

           2 mole of Fe will react with 3 moles of H₂SO₄

           8 moles of Fe will therefore yield [tex]\frac{8 x 3}{2}[/tex]   = 12 moles of H₂SO₄

Answer:

102.4 g

Explanation:

The equation of the reaction is;

2SO2(g) + O2(g) -----> 2SO3(g) --------ΔH = -198 KJ/mol

Now, given that;

If 2 moles of SO2 evolves 198 KJ/mol of heat

x moles of SO2 evolves 163 KJ/mol of heat

x = 2 * 163/198

x = 1.6 moles of SO2

molar mass of SO2 = 64 g/mol

mass of SO2 = 1.6 moles * 64 g/mol = 102.4 g

Answer: When water is added to vinegar, the vinegar's acidity decreases, which results in a higher number on the pH scale. However, diluting vinegar with water can never make it alkaline, because water itself is not alkaline; the pH of the mixture can't be higher than the higher pH value of the two components.

Explanation: it loses acidity. Diluting it can never make it alkaline and the PH mixture can’t be higher.