b. Write the formula for density.

Answer:

The answer to your question is: 3

Explanation:

If an atom has 5 electrons, 5 neutrons and 5 protons, it means that the element is Boron. Boron is situated in the third group A, that means that is has 3 elements in its outermost shell.

Also, if we do the electronic configuration:

                                                                         1s² 2s²2p¹

If we count the number of electron in the second level of energy, the result will be:    2 in s and 1 in p  = 3. Those are the valence electrons.

Lithium chloride solution most likely shows a vivid colour.

Answer: Option D

Explanation:

Flame test, an analytical strategy in chemistry to find certain elements, like metal ions, on the basis of characteristic emission spectrum of each element.

Because each element has a well-defined spectrum of linear emission, scientists can recognise it by the colour of the flame they produce.

For example, lithium and strontium red flame, nickel chloride appears as a brown or green solid, the potassium salt in the flame gives a characteristic purple colour, and hydrogen chloride as acid, a colourless gas.  Colour's dense in the order as blue > red > green > yellow.

Answer:

pressure and volume

Explanation:

Boyle's law states that the volume of a fixed mass of gas is inversely proportional to it's pressure at constant temperature.

Answer:

D. pressure and volume

Explanation:

Boyle’s law states that,

For a given amount of a gas, Pressure is inversely proportional to its volume at constant temperature

Thus the expression is

PV = constant (T and n are constant)

When there is a change in pressure and volume we make use of the expression  

[tex]P_1 V_1=P_2 V_2[/tex] (T and n are constants)

Where [tex]P_1[/tex] and [tex]V_1[/tex] are the Initial pressure and volume and

[tex]P_2[/tex] and [tex]V_2[/tex] are the final pressure and volume

Inversely proportional means when one increases the other one decreases. That is as per Boyle’s law when Pressure increases the volume will decrease and vice versa.

c. protons and neutrons are the two particles found in the nucleus of an atom

A proton is a subatomic particle found in the nucleus of every atom

Protons and neutrons are in the center of the atom, making up the nucleus. Electrons surround the nucleus. Protons have a positive charge. Electrons have a negative charge. The charge on the proton and electron are exactly the same size but opposite.

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Answer:

C

Explanation:

just took quiz

Answer:

5 g of heptane were burned.

Explanation:

Given data:

Mass of CO₂ produced = 15.5 g

Mass of heptane burned = ?

Solution:

Balance chemical equation:

C₇H₁₆ + 11O₂ →7CO₂ + 8H₂O

First of all we will calculate the moles of CO₂ produced.

Number of moles = mass / molar mass

Molar of CO₂ = 44 g/mol

Number of moles = 15.5 g / 44 g/mol

Number of moles = 0.3523 mol

Now we will compare the moles of CO₂ and C₇H₁₆ from balance chemical equation

                     CO₂      :     C₇H₁₆

                      7         :        1

                 0.3523     :        1/7 × 0.3523 = 0.05 mol

Mass of C₇H₁₆:

Number of moles = mass / molar mass

Mass = number of moles ×  molar mass

Mass =  0.05 mol / 100 g/mol

Mass = 5 g

Answer:

If you add the masses of all the products after fission, they are LESS than the mass of the reactants.

Explanation:

A nuclear fission reaction is a radioactive reaction which in which a heavy nucleus spontaneously disintegrates into 2 lighter nuclei and some neutrons with a release of large amount of energy.

When nuclear fission occurs, a mass deficit between the decaying nuclei and the product occurs. It is this mass that actually yields the energy that is produced as a by product of the reaction.

Answer:

Explanation:

The relative molecular mass of a compound the ratio of the average mass of one of its molecule compared to one-twelfth of the mass of an atom of carbon-12. It is usually expressed as grams per mole of a compound. Relative molecular mass is derieved by the addition of its component atomic masses.

Answer:

The percent composition of Protium( H¹) in nature is 99.21%.

The percent composition of Deuterium (H² )in nature is 0.79%.

Explanation:

Atomic mass of protium is 1.

Atomic mass of deuterium is 2.

These are two isotopes of hydrogen that make the total abundance of hydrogen in nature while third isotope tritium is radio active and unstable its abundance is 0%.

First of all we will set the fraction for both isotopes H¹ and H²

X for the isotopes having mass 2 amu.

1-x for isotopes having mass 1 amu.

The average atomic mass of hydrogen is 1.0079.

we will use the following equation,

2x + 1 (1-x) = 1.0079

2x + 1 - 1x = 1.0079

2x- 1x = 1.0079 - 1

1x = 0.0079

x= 0.0079/1

x= 0.0079

Percent abundance of H².

0.007 × 100 = 0.79 %

0.79% is abundance of H² because we solve the fraction x.

now we will calculate the abundance of H¹.

(1-x)

1-0.0079 =0.9921

Percent abundance of H¹.

0.9921 × 100= 99.21 %

99.21% for H¹.

The average atomic mass of hydrogen is 1.0079, which suggests that the most common isotope is H-1, but there is also a smaller amount of H-2 in nature. The specific percent composition would require more information to determine.

The average atomic mass of an element is the weighted average of the atomic masses of its naturally occurring isotopes. The fact that the average atomic mass of hydrogen is 1.0079 indicates that the most abundant isotope in nature is H-1 (hydrogen-1 or protium) which has an atomic mass close to 1. However, H-2 (hydrogen-2 or deuterium) is also present in nature, but in smaller amounts, as its atomic mass is close to 2. The slightly higher than 1 average atomic mass takes into account these two isotopes' presence and their relative abundances.

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Answer:

The question to your answer is:

Explanation:

Data

mass = 521 g

Water volume = 50.0 ml

Increase of water = 77 ml

Formula

density = mass / volume

First substract the final volume to the initial volume

Volume of gold = 77 - 50 = 27 ml

Now, use the formula

density = 521 / 27 ml = 19.3 g/ml

The density of the gold nugget is 19.3 g/mL.

To find the density of the gold, we need to calculate the volume of the gold nugget from the water displacement and then divide the mass of the gold by this volume. The volume of the gold nugget can be determined by calculating the difference in the water level before and after the gold was added. This value is 77.0 mL - 50.0 mL = 27.0 mL. Since the density (d) can be calculated using the formula d = mass/volume, we can substitute the given mass of 521 g and the calculated volume of 27.0 mL to find the density.

Using these values gives us: density = 521 g / 27.0 mL = 19.3 g/mL.

Therefore, the density of the gold is 19.3 g/mL, which is consistent with the known density of gold.

Answer:

CL

because cleetus will rule the world

Answer:

42 m/s

Explanation:

To we convert units for speed we can use dimensional analysis. First thing we do is seperate the measurement into a fraction. After this we can multiply by 1km over 0.62137 miles. We do this so that the miles cancel out.

[tex]\frac{95mi}{h}[/tex] × [tex]\frac{1km}{0.62137mi}[/tex] = [tex]\frac{95km}{0.62137h}[/tex]

After this we can use a conversion factor and divide by 3.6.

[tex]\frac{95km}{0.62137h}[/tex] ÷ 3.6 = 42 m/s

Answer:

Meanwhile

Explanation:

Think of a comic book, or a superhero show, you usually see the protagonist, or the hero, doing something like saving an innocent pedestrian, or helping a little old lady across a street, then the screen will flash and say 'meanwhile' which means while this was happening, this was also happening.

An example could be in The Wizard of Oz, when Dorothy is walking with her friends through The Haunted Forest, you see the Wicked Witch of the East, peering through her crystal ball, unto Dorothy. To summarize what was happening you could say,

'Meanwhile, as Dorothy and her friends walked through The Haunted Forest, The Wicked Witch watched their stroll.'

Really hopes this helps!

Answer:

251 g of compound contain 2.39 moles.

Explanation:

Given data:

mass of compound Al(CN)3 = 251 g

moles = ?

Solution:

First of all we will calculate the molar mass of given compound.

molar mass of Al(CN)3 = 26.98 + (26 × 3)

molar mass of Al(CN)3 = 105 g/mol

Formula:

number of moles = mass/ molar mass

number of moles = 251 g / 105 g/mol

number of moles = 2.39 mole

Answer:

3.783×10²⁴

Explanation:

We know that one mole of water contain two moles of hydrogen atom and one mole of oxygen atom. shown in following equation:

                         2H₂ + O₂ → 2H₂O

And  

1 mole of hydrogen = 6.022×10²³ atoms of hydrogen

The number 6.022×10²³ is called Avogadro number and it is the number of atoms in one mole of substance. While we have to find the hydrogen atoms in 3.14 moles of water

So the factor 3.14 given in the question contain  

3.14×2×6.022×10²³ number of hydrogen atoms which is equal to the 3.783×10²⁴.

Answer:

1.89×10^24 atoms

Explanation:

I mole of hydrogen molecule contains 6.02×10^23 atoms. This is known as the Avogadro's number. The Avogadro's number gives the number of elementary entities contained in one mole of a substance.

One mole of a substance is the amount of that substance that contains the same number of elementary entities as 12g of C-12

Hence 3.14 moles of hydrogen will contain 3.14 ×6.02×10^23= 1.89×10^24 atoms

Final answer:

A pi bond is formed by the side-by-side overlap of unhybridized 2pz orbitals on the carbon and the oxygen.

Explanation:

The pi bond is formed by the side-by-side overlap of unhybridized 2pz orbitals on the carbon and the oxygen. Just like in alkenes, the 2pz orbitals that form the pi bond are perpendicular to the plane formed by the sigma bonds.

Answer:

Nitrogen

Explanation:

Answer:

Explanation:

#9 Sodium (Na) - 0.15% - Sodium is an important electrolyte. Like potassium, it is used for nerve signaling. Sodium is one of the electrolytes that helps regulate the amount of water in the body.

Answer:

4NH3 + 5 O2  →  4 NO  + 6 H2O

Explanation:

The formula of ammonia is NH3. Oxidise  means adding 02. This will result in Nitrogen(II)oxide which is NO, and H20.

On the left side we have 3xH and on the right side we have 2x H. To get the same amount we multiply the left side bij 2 and the right side by 3.

This gives us 2N on the left side, so we multiply NO by 2, to get the same amount of N.

This gives us 5x O at the right side, so to get the same amount we multiply O2 by 5/2 ( we already got 2x O).

This gives us 2NH3 + 5/2 O2  → 2NO + 3H20

We multiply by 2 to get rid of fractions, which will give us:

4NH3  + 5 O2  → 4NO + 6H20

Answer:

V= 37.0 mL

Explanation:

First find the moles of the known substance (CuCl2)

n= cv

where

n is moles

c is concentration

v is volume ( in litres)

n= 0.108 × 0.0946

n=0.0102168

Using the mole ratio in the balanced reaction, we can find the moles of Na3PO4

n (Na3PO4)= n (CuCl2) × 2/3

=0.0102168 × 2/3

=0.0068112

Now we have all the necessary values to calculate the volume

v=n/c

v= 0.0068112/0.184

v= 0.0370173913 L

v= 37.0 mL

37 ml volume of 0.184 M Na₃PO₄ solution is necessary to completely react with 94.6 mL of 0.108 M CuCl₂ solution.

The molarity is the way to express the concentration of the solution. The molarity of any solution can be calculated by dividing the number of mos of solute by the volume of the solution in liters. The unit of the molarity of the solution is mol/L or represented by M.

Given the chemical equation of precipitation reaction:

2Na₃PO₄ (aq)  +  3CuCl₂ (aq) →  Cu₃(PO₄)₂ (s) +  6NaCl (aq)

Given the volume of 0.108 M CuCl₂ solution = 94.6 ml = 0.946 L

The number of moles of CuCl₂ = M ×V = 0.108 × 0.846 = 0.01022 mol

If 3 moles of CuCl₂ completely react with Na₃PO₄  = 2

Then 0.01022 moles of  CuCl₂ will react with Na₃PO₄ :

= (2/3) × 0.01022

= 0.00681 mol

The volume of 0.184 M of Na₃PO₄ required = 0.00681 /0.184 = 37 ml

Therefore, 37 ml of Na₃PO₄  solution is required to completely react with 94.6mL of 0.108 M CuCl₂.

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Answer:

When you have those kind of compounds you have to multiply each element inside the bracket by the subscript outside the bracket. Here you have 1 Pb, 2 N and 6 O.

Explanation:

Answer:

Replace the formulas inside the parentheses with single letters  

Explanation:

Here's an equation with lots of parentheses.

(NH₄)₃PO₄ + Pb(NO₃)₂ ⟶ NH₄NO₃ + Pb₃(PO₄)₂

It looks impossible to balance, doesn't it?

One way to balance the equation is to recognize that the polyatomic ions (the formulas inside the parentheses) stay together.

Then we can make some substitutions.

Let A = NH₄, X = PO₄, and Y = NO₃

Then the equation becomes

A₃X + PbY₂ ⟶ AY + Pb₃X₂

Here's how to balance it.

1. Start with the most complicated formula, Pb₃X₂, and put a 1 in front of it.

A₃X + PbY₂ ⟶ AY + 1Pb₃X₂

2. Balance Pb

We have fixed three atoms of Pb on the right, so we need three atoms of Pb on the left. Put a 3 in front of PbY₂.

A₃X + 3PbY₂ ⟶ AY + 1Pb₃X₂

3. Balance X

We have fixed two atoms of X on the right, so we need two atoms of X on the left. Put a 2 in front of A₃X.

2A₃X + 3PbY₂ ⟶ AY + 1Pb₃X₂

4. Balance A

We have fixed 6 atoms of A on the left, so we need 6 atoms of A on the right. Put a 6 in front of AY.

2A₃X + 3PbY₂ ⟶ 6AY + 1Pb₃X₂

Every formula has a coefficient, and the equation is now balanced.

Next, we replace the original formulas in the equation.

The balanced equation is

2(NH₄)₃PO₄ + 3Pb(NO₃)₂ ⟶ 6NH₄NO₃ + 1Pb₃(PO₄)₂

Answer:

The answer to your question is below

Explanation:

Atomic mass = 65.39 g

Searching this number in the periodic table we find that the element is Zinc.

Then:

# of Protons = 30

# of neutrons = atomic mass - # of protons

                       = 65.39 - 30

                        = 35.39

# of electrons = # of protons = 30

Answer:

Ursus: genus

Arctos: Species

Explanation:

If you think of the way the chart flows from the most broad to the most specific: kingdom, phylum/division, class, order, family, genus, species, you see that genus name comes first then the species name.

Answer:

Explanation:

High rate of speed as used by most announcers is actually not correct. Speed is the rate at which distance changes with time. Speed already expresses a rate. What one can deduce is that they probably meant to emphasize more on the how fast a sport is proceeding. Ordinarily saying speed would have been fine.

According to physics, the rate of change of speed is acceleration. Acceleration is the change in velocity with time. A body is said to be accelerating if its velocity is constantly changing.

Final answer:

When sports announcers refer to a "high rate of speed," they typically mean an object is moving quickly. In physics, 'speed' measures how fast an object moves, without direction, and is a scalar quantity. Conversely, 'velocity' includes both speed and direction and is a vector quantity.

Explanation:

When people, especially sports announcers, talk about a "high rate of speed," they are typically referring to an object, such as an athlete or vehicle, moving quickly. However, in physics, speed is a scalar quantity that measures how fast an object is moving without regard to direction, whereas velocity is a vector quantity that includes both the speed and the direction of an object's movement.

Speed can be understood as the rate at which distance is covered over time. To calculate the average speed, you would divide the total distance traveled by the elapsed time. Thus, when someone mentions a "high rate of speed," they likely mean that an object is covering distance rapidly, though they might be unintentionally conflating speed with velocity.

In the context of a race, a higher percentile speed means a faster run. For example, if the 40th percentile of speeds in a race is 7.5 miles per hour, it means that 40% of runners have a speed that is less than or equal to 7.5 miles per hour.

Answer:

The answer to your question is:  3.276 x 10³¹ Joules

Explanation:

Energy from the sun: 7.80 x 10²⁷ kcal

Look for the factor to convert units

Rule of three to convert units

                   1 cal ----------------------   4.2 Joules

           1000 cal ---------------------     x

 x = (1000 x 4.2) / 1 = 4200 Joules

                   1 kcal ----------------   4200 Joules

               7.8 x 10²⁷ kcal -------     x

           x = (7.8 x 10²⁷ x 4200) / 1 = 3.276 x 10³¹ Joules

Answer:

A. The increase in the mass of the magnesium oxide was due to oxygen atoms in the air.

Explanation:

Burning occurs in the presence of oxygen. A chemical combination occurs between Mg and O in that the atom of magnesium attracts one another.

          Mg + O₂ → MgO

Starting with the magnesium, on reacting with oxygen a new compound forms. This is why there is mass increase in the MgO compared to the starting material.

Answer: A. The increase in the mass of the magnesium oxide was due to oxygen atoms in the air.

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

The balanced chemical equation for burning of magnesium in air is:

[tex]Mg(s)+O_2(g)\rightarrow 2MgO(s)[/tex]

When magnesium combines with oxygen, the mass of magnesium oxide formed will be same as the sum of masses of magnesium and oxygen.

Thus the increase in the mass of the magnesium oxide was due to oxygen atoms in the air.

Answer:

The branch of chemistry that best describes the chemist´s work is organic chemestry

Explanation:

The chemist wants to improve the process for natural gas, a mix of organic compuond, mainly alcans.

A research to find the better way to process natural gas after it is removed from the ground is a work in organic chemistry.

Organic chemistry deals with organic compounds, their properties, reactions, uses etc. The organic compounds are hydrocarbons and its derivatives contain  carbon chains attached with hydrogen in the backbone.

Natural gases are hydrocarbons like methane, propane, butane etc. They comes under organic chemistry. All other compounds other than hydrocarbons and their derivatives are inorganic.

Hence, the research work on natural gas comes in organic chemistry thus, option A is correct.

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Answer:

Options (1), (4) and(5)

Explanation:

The earth's lithosphere is divided into two types of crust, that are commonly known as-

Both the type of crust are comprised of water, rock as well as soil. The rocks of oceanic crust are much younger than the continental crust because the oceanic crust is formed from the seafloor spreading where the new materials are added to the crust along the mid-oceanic ridge. The rocks at this boundary are the youngest. On the other hand, the continental crust is the oldest and is present from the time of the formation of the earth. The denser oceanic crust subducts below the lighter continental crust in a convergent plate boundary.

Thus, the correct answers are options (1), (4) and(5).

Answer:the answers are 1,4 and 5

Explanation:hope this helps

Answer:

A.  The object broke apart and seemed to disappear when dropped into the glass of water.

Explanation:

In a physical change, the physical properties of the matter usually the state of the matter is altered. Most physical changes are usually reversible and does not lead to the production of new substances.

When the solid object was dropped into the water beaker and it dissolves by disappearing the solution, we have experienced a physical change. This is a dissolution reaction. If we heat the solution and water given off, we can recover back the dissolved solid object.