HELP WILL GIVE BRAINLIST
How many moles of calcium are present in 199 grams of calcium?

First, we have to know the rules to recognize significant numbers:

Zeros between two non-zero digits ARE significant.

are

All non-zero numbers are significant.

Trailing zeros to the right of the decimal are significant.

Leading zeros are not significant.

Trailing zeros in a whole number with the decimal shown are significant.

Trailing zeros in a whole number with no decimal shown are not significant.

After these rules, we can say that 890 has only 2 significant numbers.

Answer: 2 significant digits

Answer:

You would want a metal that transfered heat efficiently.

Explanation:

We use metal frying pans to cook our food because they conduct heat. They are conductors of heat, if it was not so, they could not be used for cooking food.

Hope this helps! :)

Dispersion forces and dipole-dipole forces are present in pure samples of both ch₃ch₂ch₂f and ch₃ch₂ch₂oh.

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Given:

displacement(x)=18.3m

time(t)=122s

Average speed(v)=x/t

=18.3/122

=0.15m/s

Therefore,the train's average speed=0.15m/s

Answer:

21.107

Explanation:

because this answer gives you 10 and also 90

The balanced reaction equations are given below. They are all examples of double displacement.

a) balanced reaction equation of the reaction between aqueous copper(II) nitrate and aqueous potassium hydroxide, resulting in the formation of solid copper(II) hydroxide and aqueous potassium nitrate

[tex]Cu(NO_{3} )_{2}(aq)+2KOH(aq)[/tex] → [tex]Cu(OH)_{2} (s) + 2KNO_{3}(aq)[/tex]

b) balanced reaction equation of the double displacement between gaseous boron cyanide and liquid water resulting in the formation of solid boric acid and gaseous hydrogen cyanide

[tex]2B(CN)_{3} (g) + 6H_{2} O[/tex] → [tex]2H_{3} BO_{3} (s)+6HCN(g)[/tex]

c) balanced reaction equation between solid calcium silicate and gaseous hydrogen fluoride resulting in the formation of gaseous silicon fluoride, solid calcium fluoride and liquid water

[tex]CaSiO_{3}(s) + 6HF (g)[/tex] → [tex]SiF_{4}(g)+CaF_{2}(s)+3H_{2}O(l)[/tex]

d) balanced reaction equation between cyanogen gas and liquid water resulting in formation of aqueous oxalic acid and gaseous ammonia

[tex](CN)_{2}(g) + 4H_{2} O (l)[/tex] → [tex]H_{2} C_{2} O_{4} (aq) +2NH_{3} (g)[/tex]

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The difference between covalent and ionic bonds is that covalent bonding allows atoms to share electrons, but ionic bonding cause electron transfer, leading the atoms to form ions (cations and anions), and these oppositely charged ions are attracted to each other.

Atoms combine to create compounds in order to complete their octet and to achieve stability. This can be done by combining with other atoms either by electron sharing or electron transfer from one atom to another. Therefore, covalent bonds are created when electrons are shared, whereas ionic bonds are created when electrons are transferred.

Ionic bonds are generally formed between metal and nonmetal atoms. Non-metallic atoms gain electrons to form a negatively charged ion, while metallic atoms lose electrons to form positively charged ions. An atom becomes a cation when one or more of its electrons are lost, while an atom forms an anion when one or more electrons are gained. Hence, an ionic bond is formed as a result of the electrostatic attraction between oppositely charged ions.

A covalent bond, on the other hand, is formed between non-metal atoms as a result of electron sharing.

Therefore, an ionic bond is an attraction between ions with opposite charges whereas a covalent bond is the sharing of electrons between atoms.

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There's approximately 15.8 g of NaOCl in a cup of bleach. To calculate this we need to use the molarity of the bleach solution and the molar mass of sodium hypochlorite.

In order to convert the molarity to mass, we need the molar mass of sodium hypochlorite. We can calculate it by adding up the relative atomic masses of sodium (23), oxygen (16), and chlorine (35.5):

M (NaOCl) = (23 + 16 + 35.5) g/mol = 74.5 g/mol

Now we calculate the amount (in moles) of sodium hypochlorite present in 250 mL (0.25 L) of bleach:

c = n/V ⇒ n = c*V = 0.850 M * 0.250 L = 0.2125 mol of NaOCl

Using the molar mass, we can now calculate the mass required:

n = m/M ⇒ m = n*M = 0.2125 mol * 74.5 g/mol = 15.8 g of NaOCl

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Answer:

false

Explanation:

can carry heat, not communication

 The correctly identified subatomic particle with its charge is  

The British physicist James Chadwick made the neutron discovery in 1932.

Neutrons are neutral subatomic particles that are a part of every atomic nucleus, except the exception of regular hydrogen. Its rest mass of 1.67927980 10-27 Kg is slightly larger than a proton but 1838.68 times greater than an electron. It has no electricity charge. The dense inner core of the atom is where protons and neutrons, collectively referred to as nucleons, are linked together and account for 99.9% of the mass of the atom.

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Using ideal gas laws and the balanced reaction equation for the combustion of butane, we can calculate that the volume of produced carbon dioxide will be 25.6 L.

The balanced reaction equation for butane combustion looks like this:

[tex]2C_{4} H_{10} + 13O_{2}[/tex] → [tex]8CO_{2}+10H_{2} O[/tex]

We can see that 2 moles of butane (M = 58 g/mol) produce 8 moles of carbon dioxide. This allows us to set up a proportion that we can use to calculate the amount of carbon dioxide produced by the combustion of 14.0 g of butane:

116 g of butane : 8 moles of carbon dioxide = 14.0 g of butane : X

X = 8 moles of carbon dioxide * 14.0 g / 116 g = 0.9655 mol of carbon dioxide

Now, using the ideal gas laws, we can calculate the volume of released carbon dioxide.

PV = nRT ⇒ V = nRT/P = 0.9655 mol * 0.08206 Latm/Kmol * (25 + 273) K / 0.922 atm = 25.6 L

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Based on the number of particles involved and the enthalpy of the reaction, changes that would shift the equilibrium to the right would, according to Le Chatelier's principle, include increasing the volume of the system, reducing the pressure of the system, reducing the temperature of the system, increasing the concentration of ammonia and/or oxygen and reducing the concentration of NO and/or water. Changes in the opposite direction would cause the equilibrium to shift towards the reactants.

Upon increasing pressure or reducing volume, the equilibrium shifts in the direction that produces fewer gaseous particles. In this case, that's the reactants (9 molecules) and not the products (10 molecules). When considering temperature, it is useful to consider heat as one of the reaction components. When the enthalpy of the reaction is negative, heat is produced so it can be considered to be one of the products. Le Chatelier's principle states that upon changing one of the variables, the equilibrium will shift in the direction that counteracts the effects of the change. So, when reducing the temperature of the system, we are taking the heat out of the system, so equilibrium will shift to the products so that it can produce more heat, and vice versa. The same principle applies to the concentrations of ammonia, oxygen, water, and NO.

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The alum produced during experiment for every 210 can is 38.21 kg

Experiment can be defined as a technique used to establish or refute a hypothesis, or to determine the efficacy or likelihood of anything new.

It can also be defined as a series of acts and observations carried out in the context of attempting to solve a specific problem or question.

According to your experiment 0.4996 gram of aluminum will produce 5.183 grams of alum.

Mass of 1 aluminum can = 13.5 g

Mass of 210 can = 13.5 x 210 = 2835g

Mass of alum produced by one gram of aluminum = 13.48 g

Mass of alum produced by 2835 g = 13.48 x 2835

                                                          = 38.21 kg

The amount of alum produced by 210 can = 38.21 kg

Thus, the alum produced during experiment for every 210 can is 38.21 kg

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1. Iceberg

2. The iceberg is more underwater than the ship.

Thanks to radar technology better crew training and iceberg monitoring systems, ship collisions with icebergs are generally avoidable, but when a collision does occur, the consequences can be devastating. These things are very rare. One of the rare but high-impact risks. The Titanic was neither the first nor the last ship to hit an iceberg and sink.

Here are the ten most sunk ships in the world in terms of lives lost due to iceberg accidents. A second study by British historian Tim Martin argued that atmospheric conditions on the night of the disaster may have caused a phenomenon called super refraction. This diffraction of light may have created a mirage or optical illusion that obscured the iceberg from the Titanic's vantage point.

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1) This is an Anion

2) This is a Cation

3) It is Neutral.

Atom: A chemical element is uniquely defined by its atoms, which are tiny pieces of substance. An atom is made up of a core nucleus and one or more negatively charged electrons that orbit it. The positively charged, comparatively hefty protons and neutrons that make up the nucleus may be present.

1) number of protons = 7

So, the atomic number = 7

N has an atomic number of 7.

charge = number of proton - number of electrons

= 7 - 10

= -3

So, this is an anion

symbol: N3-

atoms or ion: anion

number of protons = 7

number of electrons = 10

2) charge = +3

Pd has an atomic number of 46.

number of protons = 46

charge = number of proton - number of electrons

+3 = 46 - number of electron

number of electron = 43

since the charge is positive it is a cation

symbol: Pd3+

atoms or ion: cation

number of protons = 46

number of electrons = 43

3) number of protons is 28

So, the atomic number is 28

Ni has an atomic number of 28.

since it is neutral,

number of electron = number of proton = 28

symbol: Ni

atoms or ion: neutral atom

number of protons = 28

number of electrons = 28

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The percentage by mass of hydrogen in the Compound that is formed is found to be 5% if 1.0g of hydrogen reacts Completely with 19.0g of fluorine.

A component in a particular combination or a concentration can be described using the mass percent symbol. The mass of solute contained in a specific mass of solution is indicated by the mass percentage used to characterize the solution composition. The concentration of the solute is expressed in terms of mass or moles.

As a mass percentage, an element's concentration in a compound or component of a combination can be represented. The mass percentage is calculated by multiplying the result by 100% after dividing the combined mass by the masses of each component. Also called Mass Percent or (w/w) Percent.

[tex]\frac{1}{2} H_{2} + \frac{1}{2} F_{2}[/tex] →[tex]HF[/tex]

Percentage by mass hydrogen

= (Mass of hydrogen) / (Mass of Hydrogen fluoride) x 100%

= [tex]\frac{1}{20}[/tex] x 100%

=5%

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a)The 4.48 mol H₂O₂ contains 8.96 moles of oxygen atoms.

b)The 2.15 mol N₂O contains 2.15 moles of oxygen atoms.

c)The 0.0237 moles H₂CO₃ contains 0.0711 moles of oxygen atoms.

d)The 24.1 mol CO₂ contains 48.2 moles of oxygen atoms.

A mole is 6.02214076 x 1023 of any chemical unit, comprising atoms, molecules, ions, and others. Due to the large number of atom, molecules, or other components that comprise any material, the mole is an useful unit to utilize.

There are two moles of H and two moles of O in every mole of H₂O₂

There are two moles of N and one mole of O in every mole of N₂O

There are 2 moles of H, 1 mole of C, and 3 moles of O in a mole of H₂CO₃

1 moles of C and 2 moles of O are present for every mole of CO₂

Taking this into account:

The number of moles of oxygen atoms present in a 4.88 moles sample of H₂O₂ can be determined by:

[tex]\text { 4.48 molesof } \mathrm{H}_2 \mathrm{O}_2 x \frac{2 \text { moleso foxygen }}{1 \text { moleof } \mathrm{H}_2 \mathrm{O}_2}=[/tex]8.96 moles of oxygen atoms

The 4.48 mol H₂O₂ contains 8.96 moles of oxygen atoms.

The number of moles of oxygen atoms present in a 2.15 moles sample of N₂O can be determined by:

[tex]2.15 \text { molesof } N_2 O x \frac{1 \text { molesofoxygen }}{1 \text { moleof } N_2}=[/tex]2.15 moles of oxygen atoms

The 2.15 mol N₂O contains 2.15 moles of oxygen atoms.

The number of moles of oxygen atoms present in a 0.0237 moles sample of H₂CO₃ can be determined by:

[tex]0.0237 \text { molesof } \mathrm{H}_2 \mathrm{CO}_3 x \frac{3 \text { moleso foxygen }}{1 \text { moleof } \mathrm{H}_2 \mathrm{CO}_3}=[/tex]0.0711 moles of oxygen atoms

The 0.0237 moles H₂CO₃ contains 0.0711 moles of oxygen atoms.

The number of moles of oxygen atoms present in a 24.1 moles sample of CO₂ can be determined by:

[tex]24.1\text { molesofC } \mathrm{CO}_2 x \frac{2 \text { moleso foxygen }}{1 \text { moleof } \mathrm{CO}_2}[/tex]=48.2 moles of oxygen atoms

The 24.1 mol CO₂ contains 48.2 moles of oxygen atoms.

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No, this item is not made of pure silver because if it has been made from pure silver that it would have displaced only 1.16cm³ of water but due to the addition of some other low-density element it displaces 1.9cm³ of water.

For pure silver

density of pure silver is = 10.49 g/cm³

mass of silver = 12.2 gram

since, density = mass/volume

          volume = mass/density

                        = 12.2/10.49 cm³

                         = 1.16 cm³

But the actual displaced water is 1.9cm³, which means some other element of lower density has been added.

Therefore, it is clear that the given jewelry is not made of pure silver.

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Theoretical mass (O₂)= H₂O₂ Volume×  H₂O₂ density× {( 1 mol O₂)/(2 mol H2O2)}×{( mol of  H₂O₂ /g  H₂O₂ )}

H2O2 Volume= 5 ml

Known density( H₂O₂ )= 1.02 g/ml

Molar mass ( H₂O₂ )= 34.01 g/mol

Reciprocal molar mass(  H₂O₂ )= 0.0294

Theoretical mass( O₂)= 5×1.02× 0.0294× 1/2= 0.0749 moles

Actual moles of O₂ and percentage of  H₂O₂

P= 753 mm Hg×1 atm/760 mm Hg= 0.991 atm

V= 45  ml× 1L /1000 ml= 0.045 L

n= PV/RT

Actual moles ( O₂)= (0.991×0.045)/(0.0821×296 K)= 0.0445/24.3016= 1.8×10^-3 moles

Percentage ( H₂O₂ )= Theoretical moles(O₂)×100= 0.0749×100= 7.49%

Mass of  H₂O₂ (percent)= 3%

Concentration by mass( H₂O₂ )= 3 gm H2O in 100 ml of H2O

Volume ( H₂O₂ )= 100 ml

1 mol ( H₂O₂ )= 34.02 g O2

(3g  H₂O₂ /100 ml Solution)×( 1 mol  H₂O₂ /34.02 g H2O2)

No. Of moles ( H₂O₂ )= 0.088 moles

Mass ( H₂O₂ )= 0.088 moles × 34.02 = 2.99 g

%  H₂O₂ = (2.99 g  H₂O₂ /100 ml Solution)×100= 2.99%

% error= (%  H₂O₂ from the bottle-experiment %  H₂O₂ )/(% H₂O₂ from bottle)×100

=[ (3-2.99)/(3) ]× 100= 0.34% error.

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Answer:

It is a neutralization reaction.

The age of the granite given it contains 25% parent (uranium-235) and 75% daughter (lead-206) is 1408 million years

We'll begin by calculating the number of half lives that has elapsed. This can be obtained as follow:

2ⁿ = N₀ / N

2ⁿ = 100 / 25

2ⁿ = 4

2ⁿ = 2²

n = 2

The age of the granite can be obtained as follow:

n = t / t½

Cross multiply

t = n × t½

t = 2 × 704

t = 1408 million years

From the calculations made above, we can conclude that the age of the granite is 1408 million years

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Answer:

Silicone

Explanation:

Silicone matches all the things

Vinegar or acetic acid(CH3COOH) has intermolecular forces  of hydrogen bonding, dipole-dipole interactions and dispersion force.

Intermolecular forces can be defined as the attractive and repulsive forces that arise between the molecules of a substance.

Intermolecular forces includes the electromagnetic forces of attraction or repulsion which act between atoms and other types of its close particles such as atoms or ions.

Vinegar or acetic acid(CH3COOH) has intermolecular forces  of hydrogen bonding, dipole-dipole interactions and dispersion force.

Vinegar or acetic acid(CH3COOH)  has an especially strong type of hydrogen bonding. In solid state, the molecules in the acetic acid form cyclic pairs connected by hydrogen bonds. Thus, making it to have a low volatility.

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The number of electrons can be predicted in a neutral atom  because the number of protons and electrons in a neutral atom will be identical, we can readily calculate the electron number from the atomic number.

An atom's atomic number can be used to forecast its electrical structure. The atomic number can be used to forecast the total number of electrons because neutral atoms have an equal number of protons and electrons.

So, If you know what group the atom's element belongs to and the group number correlates to the number of electrons on the valence shell and you can determine how many atoms are on the atom's valence shell.

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Going by the remnant charge, if a negatively charged substance is brought near the ion, an attraction will take place. The ion will attract the substance because the ion has more protons than electrons.

According to established law, substances with like charges repel one another while those with unlike charges tend to attract.

Considering the ion in question, there are 3 positive and 2 negative charges. This means that the ion has one remnant positive charge. In other words, the ion has more protons than electrons.

If a substance that is negatively charged is brought near the ion, an attraction will take place. This is because both the ion and the substance have unlike charges.

In summary, there will be an attraction between the ion and the substance because the ion has more protons (positive charges) than electrons (negative charges).

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Answer:

The ion will repel the substance because the ion has more protons than electrons.

Explanation:

Because the ion has more protons than electrons the ion will repel the substance :)

Answer:

N-16

Explanation:

Atom has 7 protons so it's atomic number is 7, which is Nitrogen

so isotope is 7 + 9 = 16

then it's N-16

Answer: supercalifragilisticexpialidocuos

Explanation:

The student observed the solution before it wind put into the flame and realized it was similar in texture and colour to,  the lithium chloride the teacher showed them. When they  saw that both lithium chloride and the unknown produced a red flame, they were sure that the unknown must have been lithium chloride as well

A compound refers to a substance consisting of identical molecules composed of atoms of two or more chemical elements.  That is called a chemical compound. A chemical compound means a chemical substance consisting of several similar molecules containing elements of several elements.

Most notably, these molecules are linked by chemical bonds.  A chemical formula expresses the number of atoms of each element in a molecule of a compound. In addition, this chemical formula uses standard abbreviations for chemical elements with numerical signatures.

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Answer:

The chemical reaction 2H2+O2→2H2O 2 H 2 + O 2 → 2 H 2 O is classified as a synthesis reaction.

Explanation: