1. The center of the atom is called the
(10 Points)
O nucleus
O protons
electrons
neutrons

Answer:

2Cr³⁺(aq) + 3S²⁻(aq) ----> Cr₂S₃(s)

Explanation:

When aqueous solutions of chromium(III) chloride and ammonium sulfide are  mixed together, chromium (III) chloride and ammonium sulfide undergoes a double displacement reaction to produce chromium (iii) sulphide as a precipitate and ammonium chloride which remains in solution.

The general equation of the reaction is given below:

2CrCl₃(aq) + 3(NH₄)₂S(aq) ----> Cr₂S₃(s) + 6NH₄Cl(aq)

The net equation of the reaction is given below:

2Cr³⁺(aq) + 3S²⁻(aq) ----> Cr₂S₃(s)

Answer:

Thus, at convergent boundaries, continental crust is created and oceanic crust is destroyed. Two plates sliding past each other forms a transform plate boundary. Natural or human-made structures that cross a transform boundary are offset—split into pieces and carried in opposite directions.

Explanation:

Answer:

112.92 s.

Explanation:

Let M₁ be the molar mass of N₂O

Let t₁ be the time taken for N₂O to effuse.

Let M₂ be the molar mass of I₂

Let t₂ be the time taken for I₂ to effuse.

Molar mass (M₁) of N₂O = (14×2) + 16 = 28 + 16 = 44 g/mol

Time (t₁) of effusion of N₂O = 47 s

Molar mass (M₂) of I₂ = 127 × 2 = 254 g/mol

Time (t₂ ) of effusion of I₂ =?

The time take for the same amount of I₂ to effuse can be obtained as follow:

t₂/t₁ = √(M₂/M₁)

t₂/47 = √(254 / 44)

Cross multiply

t₂ = 47 × √(254 / 44)

t₂ = 112.92 s

Therefore, it will take 112.92 s for the same amount of I₂ to effuse.

Answer:

The answer is true

Explanation:

bc I took this on edgeunity

Answer:

Neon

Explanation:

All noble gases have 8 valence electrons except helium.

Noble gases include Helium, neon, argon, krypton, xenon, redon.

Electronic configuration of neon:

Ne₁₀ = [He] 2s² 2p⁶

All other options are incorrect because,

Electronic configuration of Fluorine:

F₉ = [He] 2s² 2p⁵

Fluorine have seven valence electrons.

Electronic configuration of oxygen:

O₈ = [He] 2s² 2p⁴

Oxygen have six valence electrons.

Electronic configuration of sodium:

Na₁₁ = [Ne] 3s¹

sodium have one valence electron.

Answer:

s = 22.352 m/s

Explanation:

Given data:

Time taken = 0.5 hours

Distance cover = 25 miles

Car speed = ?

Solution:

First of all we will convert the units.

1 hour = 3600 sec

0.5 hr ×3600 sec / 1hr = 1800 sec

miles to meter:

25 mi × 1609 m/ 1 mi = 40233.6 m

Formula:

s =  d/t

s = speed

d = distance

t = time

Now we will put the values in formula.

s = 40233.6 m / 1800 sec

s = 22.352 m/s

Answer:

Strong electrolytes-2,4

Weak electrolyte-1,5

Non electrolyte- 3,6

Explanation:

The statements were labeled according to whether they define strong electrolytes, weak electrolytes or non electrolytes.

Strong electrolytes are completely dissociated in solution and form highly ionic solutions.

Weak electrolytes have medium conductivity and do not completely dissociate in solution.

Non electrolytes do not dissociate in solution and their solution does not conduct electricity.

1. Weak electrolyte solution: it contains a partially dissociated solute.

2. Strong electrolyte solution: it has the highest conductivity.

3. Non-electrolyte solution: it contains a complete solute.

4. Strong electrolyte solution: it contains a completely dissociated solute.

5. Weak electrolyte solution: it has a medium level of conductivity.

6. Non-electrolyte solution: it has little or no conductivity.

A solution can be defined as a homogenous mixture that contains two or more substances.

In Chemistry, there are three (3) main types of solution and these include:

1. Weak electrolyte solution: this is a type of solution in which only a small amount of dissolved solute exists as ions because it partially dissociates into its constituent anions and cations.

2. Strong electrolyte solution: this is a type of solution that contains only ions but no molecules of the electrolyte because it completely dissociates or ionizes in a solution.

3. Non-electrolyte solution: this is a type of solution that do not dissociates or ionizes in a solution.

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Answer:

T

Explanation:

A Spider is a creepy crawly with no vertebrae and more than 6 jointed legs.

The Spider belongs to the class Arachnida . The Spider can be referred to as a non-vertebrates hence , they don't have a vertebrae(backbone).

The Spider and Cockroach are both non-vertebrates but with different pairs of legs. A cockroach is belongs to the class Insecta in which those under this class have only six jointed legs.

The Spider has eight jointed legs which is more than six and is a characteristic of Arachnids.

A snake on the other hand is a vertebrate which exempts it from being the answer.

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Answer:

From these two values, i.e. mass and volume, density of the copper cylinder can be calculated.

Formula of density is :

Density = Mass / volume.

Now we have mass: 53.76g and volume 6cm³

Density = 53.76 / 6

Density= 8.96 g/cm³

Answer: Wax

Explanation:

Density is defined as the mass contained per unit volume.

[tex]Density=\frac{mass}{Volume}[/tex]

Usually solids are more denser than liquid, as molecules in solid are more strongly packed and thus have more mass per unit volume.

Liquids on the other hand contain molecules which are less tightly bound and thus thus contain less mass per unit volume as compared to solid.

Example: Solid wax is more denser than liquid wax.

Answer: The size actually does not matter. But planets with smaller mass will have less gravity decreasing their weight. Other for larger mass planets, more mass is more gravity which is also more weight.

Explanation:

Answer: the last one

Explanation: if a cell has too little water, it will begin to function incorrectly, and if a cell has too much water it will burst.

Answer:

1. Caffeine, C₈H₁₀N₄O₂

Amount = 1.00/194 = 0.00515 moles

2. Ethanol, C₂H₅OH

Amount = 0.0217 moles

3. Dry Ice, CO₂

amount = 0.0227 moles

Note: The question is incomplete. The compound are as follows:

1. Caffeine, C₈H₁₀N₄O₂;

2. Ethanol, C₂H₅OH;

3. Dry Ice, CO₂

Explanation:

Amount (moles) = mass in grams /molar mass in grams per mole

1. Caffeine, C₈H₁₀N₄O₂

molar mass of caffeine = 194 g/mol

Amount = 1.00 g/194 g/mol = 0.00515 moles

2. Ethanol, C₂H₅OH

molar mass of ethanol = 46 g/mol

Amount = 1.00 g/46 g/mol = 0.0217 moles

3. Dry Ice, CO₂

molar mass of dry ice = 44 g/mol

amount = 1.00 g/44 g/mol = 0.0227 moles

The question is incomplete, the complete question is;

Compare Homogeneous and Heterogeneous Equilibria Question Which type of equilibrium is more likely to omit substances from the equilibrium constant expression? Select the correct answer below: O homogeneous equilibria O heterogeneous equilibria O a and b are equally likely O there is no correlation

Answer:

heterogeneous equilibria

Explanation:

In a heterogeneous equilibria, there are species of different phases present in the equilibrium expression. Some of these heterogeneous substances may be pure solids.

Remember that the solids and pure liquids are eliminated from the final equilibrium expression.

Thus, when writing equilibria involving heterogeneous substances, solids and pure liquids do not appear in the final equilibrium expressions.

Answer:

see explanation

Explanation:

When caffeine is purified, the impurities are removed,  these impurities are responsible for the greater mass of pure caffeine compared to the mass of the pure sample.

The percent recovery of caffeine is frequently low because some caffeine is often left behind in the solvent during the process of recrystallization.

Secondly, since caffeine is a sublime substance, some caffeine may be lost o sublimation leading to a low percent recovery of pure caffeine.

Answer:

D represents the element nitrogen which will gain three valence electrons forming a 3 ion.

Answer:

answer is

Explanation:

D

Answer:

Explanation:

From the given information;

the molecular molarity of the acid and  base are as follows:

For acid : 5 mL × 0.20 M = 0.1 mmol

For base: 5 mL × 0.20 M = 0.1 mmol

However;

0.05 m  × 1.0 M = 0.05 mmol of acid HCl

Similarly, When the acid undergoes reaction with the base; the amount of acid and base left are as follows:

Amount of acid left:

0.1 + 0.05 = 0.15 mmol

Amount of base left:

0.1 - 0.05 = 0.05 mmol

The formula for calculating the Buffer pH is:

[tex]pH = pka + log(\dfrac{Base}{Acid} )[/tex]

Recall that for Acetic, the acid dissociation constant = 4.74

Then:

[tex]pH =4.74+ log(\dfrac{0.05}{0.15} )[/tex]

[tex]pH =4.74+ log(0.333)[/tex]

pH = 4.74 -  0.4775

pH = 4.26

Therefore, the decrease in pH is about 0.48 units

Answer:

A high-pressure area, high, or anticyclone, is a region where the atmospheric pressure at the surface of the planet is greater than its surrounding environment. Winds within high-pressure areas flow outward from the higher pressure areas near their centers towards the lower pressure areas further from their centers.

Explanation:

Answer:

a. 0.183 mol C

b. 0.366 mol H

Explanation:

Assuming total combustion, all of the carbon in the unknown compound turned into carbon dioxide, CO₂.

So first we calculate the CO₂ moles produced, using its molecular weight:

This means in the unknown compound there were 0.183 moles of carbon, C.

Conversely, all of the hydrogen in the unknown compound turned into water, H₂O.

Calculating the H₂O moles:

We multiply the water moles by two, as there are 2 H moles per H₂O mol:

Answer:

It was formed from slow cooling.

the angle of the Sun’s rays

Explanation:

Answer:

D. It was formed from slow cooling.

Answer:

WCl₂, WCl₄, WCl₅, WCl₆

Explanation:

Molar Mass of Tungsten = 184 g/mol

Mass of Chlorine = 35.5 g/mol

In the first compound;

Percentage of tungsten = 72.17 %

Upon solving;

72.17 % = 184

100 % = Total mass

Total mass of compound = 254.95g

Mass of chlorine = 254.95 - 184 = 70.95 (Dividing by 35.35; This is approximately 2 Chlorine atoms.

The Formular is WCl₂

In the second compound;

Percentage of tungsten = 56.45 %

Upon solving;

56.45 % = 184

100 % = Total mass

Total mass of compound = 325.95 g

Mass of chlorine = 325.95 - 184 = 141.95g (Dividing by 35.35; This is approximately 4 Chlorine atoms.

The Formular is WCl₄

In the third compound;

Percentage of tungsten = 50.91 %

Upon solving;

50.91 % = 184

100 % = Total mass

Total mass of compound = 361.42 g

Mass of chlorine =  361.42 - 184 = 177.42 (Dividing by 35.35; This is approximately 5 Chlorine atoms.

The Formular is WCl₅

In the fourth compound;

Percentage of tungsten = 46.39 %

Upon solving;

46.39 % = 184

100 % = Total mass

Total mass of compound = 396.64 g

Mass of chlorine = 396.64 - 184 = 212.64 (Dividing by 35.35; This is approximately 6 Chlorine atoms.

The Formular is WCl₆

Answer:

When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the iodide ion will be __6__.

Explanation:

From the redox equation, we can see that NO₃⁻ is reduced to NO (from oxidation state +5 to +2), whereas I⁻ is oxidized to I₂ (from oxidation state -1 to 0). The half reactions are balanced with H⁺ (acidic solution), as follows:

Reduction :        2 x (NO₃⁻(aq) + 3 e-  + 4 H⁺ → NO(g) + 2 H₂O)

Oxidation :                                   3 x (2 I⁻(aq) → I₂(s) + 2 e-)

                       ----------------------------------------------------------------------

Total equation: 6 I⁻(aq) + 2 NO₃⁻(aq)+ 8 H⁺ → 3 I₂(s) + 2 NO(g) + 4 H₂O

That is the redox equation with the smallest whole number coefficients.

Accordin to this, the coefficient for the iodide ion (I⁻) is: 6.

The given redox equation is balanced with the smallest whole-number coefficients, the coefficient for the iodide ion will be 6.

Redox reaction is the reaction in which oxidation and reduction both occur simultaneously.

From the redox equation, we can see that NO₃⁻ is reduced to NO (from oxidation state +5 to +2), whereas I⁻ is oxidized to I₂ (from oxidation state -1 to 0).

The half reactions are balanced with H⁺ (acidic solution), as follows: Reduction : 2 x (NO₃⁻(aq) + 3 e- + 4 H⁺ → NO(g) + 2 H₂O)

Oxidation : 3 x (2 I⁻(aq) → I₂(s) + 2 e-) ----------------------------------------------------------------------Total equation: 6 I⁻(aq) + 2 NO₃⁻(aq)+ 8 H⁺ → 3 I₂(s) + 2 NO(g) + 4 H₂O

That is the redox equation with the smallest whole number coefficients.

According to this, the coefficient for the iodide ion (I⁻) is: 6.

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Answer:

Explanation:

It will take 3 sodium ions to neutralize 1 phosphorus ion. That's because you need 3 plus's to satisfy the - charge on phosphorous. So the chemical formula is Na3P reflecting this fact.

The physical changes are:

The chemical changes are:

Matter can undergo 2 kinds of changes:

Let's consider the following text.

When my alarm went off at 70'clock, I hit snooze" a few times then finally got out of bed with excitement for my morning bowl of cereal. I poured the cereal and milk into my bowl. But before I even drank it, I could tell from the smell that the milk had soured! So, I decided to blend up a banana smoothie instead. I took some ice out of the freezer and grabbed the only banana that we had in the kitchen, which was covered in brown spots. My grumbling stomach needed to be satisfied before school so I didn't really care.

Just as I was sitting down to drink my smoothie my little brother came bounding into the kitchen and asked, Would you make some eggs and toast for me for breakfast?

"Ugh, sure," I said. I cut a piece of bread in half and put it in the toaster, then I cracked two eggs and whipped them with a fork. I reached for one of my mother's copper cooking pans in the cabinet and saw that it was completely tarnished! I didn't want to be blamed for this, so I ran to tell my mother right away. As I ran out of the kitchen slipped on that banana peel and it smeared all over the floor. As I lay on the floor with the wind knocked from me, I noticed that our family's plants were dying and that some water had evaporated from our fish tank. I made a mental note to take care of these things after school.

Just as I regained my breath and stood up, I heard glass breaking upstairs and my mother shrieking. I ran up the stairs, breathing heavily now. Steam was rolling out from the open bathroom door. When the steam cleared, saw why my mother had been screaming. Before me was my older sister standing in the bathroom with purple hair. I inferred from the scene that my mother had dropped a glass when she first saw her look what your sister did to her hair my mother yelled furiously I decided that I needed to get out of the house immediately, this morning was a crazy one!

A distinct smell was waiting up the stairway and I realized that my brother's toast must be burning! When reached the kitchen, my brother was happily spreading butter on his very browned toast. "I like my toast really crispy!" he said.

"Good I can't handle any more chaos this morning! I exclaimed. I grabbed my backpack headed out into the foggy morning air, and hopped on my slightly rusted bicycle to ride to school. A few minutes into my ride, my stomach grumbled and I realized that I never got a chance to drink my banana smoothie. Luckily, I had stashed a chocolate bar in my backpack yesterday. "Yes! I thought as I stopped pedaling, grabbed the chocolate and broke off a piece. As the chocolate melted in my mouth, I knew that my day was bound to get better!

The physical changes are:

The chemical changes are:

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Answer:

[tex]p_2=5.17torr[/tex]

Explanation:

Hello.

In this case, by using the Clausius-Clapeyron Equation which allows us to relate the vapor pressure, temperature and heat of vaporization as shown below:

[tex]ln(\frac{p_1}{p_2} )=\frac{\Delta _vH}{R}(\frac{1}{T_2}-\frac{1}{T_1} )[/tex]

Whereas [tex]p_1[/tex] is 760 torr due to the normal conditions. In such a way, for computing the vapor pressure of benzaldehyde at 53.5 °C (326.65 K), we proceed as shown below:

[tex]\frac{p_1}{p_2} =exp[\frac{48800J/mol}{8.314\frac{J}{mol*K}}(\frac{1}{326.65K}-\frac{1}{451.0K} )]\\\\\frac{p_1}{p_2}=147.0[/tex]

Thus, the vapor pressure at the final T is:

[tex]p_2=\frac{p_1}{147.0}=\frac{760torr}{147.0}\\ \\p_2=5.17torr[/tex]

Best regards!

Answer:

Mark as brainleist answer and thanks this answer

Explanation:

no of moles = no of atoms ÷ avogadro's number

= (9.8×10^24) ÷ (6.02×10^23)

Answer:

the answer is B

Explanation:

When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges