How can the number of core electrons be determined from the periodic table?

A. By finding the atomic number minus the group number

B. By finding the atomic number minus the period number

C. By finding the atomic number plus the group number

D. By finding the group number plus the period number

Answer: Exothermic reactions are reactions or processes that release energy, usually in the form of heat or light.

Explanation: In an exothermic reaction, energy is released because the total energy of the products is less than the total energy of the reactants.

To reduce the concentration of oxiconazole nitrate (oxistat) lotion to 6 mg/ml, we need to add a certain amount of lotion base.

We can use the formula C1V1 = C2V2 to find the amount of lotion base that needs to be added.
C1 = initial concentration of oxiconazole nitrate = 1% w/v = 10 mg/ml
V1 = initial volume of oxiconazole nitrate = 30 ml
C2 = final concentration of oxiconazole nitrate = 6 mg/ml
V2 = final volume of oxiconazole nitrate = V1 + V (where V is the volume of lotion base that needs to be added)
Substituting the values into the formula:
10 mg/ml × 30 ml = 6 mg/ml × (30 ml + V)
Simplifying:
300 mg = 180 mg + 6V
Rearranging:
6V = 120 mg
V = 20 ml
Therefore, 20 ml of lotion base must be added to 30 ml of oxiconazole nitrate (oxistat) lotion 1% w/v to reduce its concentration to 6 mg/ml.

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Secondary amine is what it is. Option (B3-dimethylbutan-2-amine )'s is the primary organic product created during the following reaction. Thus, if more hydrogen is added to carbon, we will obtain the main product, according to the Markovnikov Rule.

As a result, the main product produced by adding hydrogen to carbon-1, which has a higher concentration of hydrogen, and adding bromine to carbon-2 is 2-bromopropane. When a reaction follows Markovnikov's rule, a chemical or product is said to be a major organic product. The tertiary alkyl iodide is the largest byproduct of the second process, which transforms alcohol into alkyl iodide, while the secondary alkyl iodide is the minor byproduct.

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Answer:

raising the Concentration of liquid

raise the temperature of the system

bubbles of hydrogen gas

The percentage of H₂O in magnesium sulfate ,MgSO₄.7H₂O is 51.2

Epsomite or Epsom salt is a hydrous magnesium sulfate mineral with formula MgSO4·7H2O .Epsom salt is very useful in relaxing muscles and relieve pain in the shoulders, neck and back.

Magnesium in Epsom salt help release  headache or migraine by relaxing the muscles surrounding your skull. This benefit can also help in sore muscles during the recovery period after a workout session.

Relative molecular mass of MgSO₄.7H₂O

=24+32+(16×4)+7(2+16)

=24+32+64+126=246

26g of Epsom salt contains 126g of water of crystallization.

Hence, 100g of Epsom salt contains 100×126/246

The percentage of mass of water in magnesium sulfate is 51.2

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Answer: Textured sides, smooth sides, wipe down.

Answer:

3.374L

Explanation:

According to Charle's Law:

V1/T1=V2/T2 (At constant pressure and moles)

where V=Volume and T=Temperature.

The temperature must be in kelvin.

K=C°+273

T1=40+273=313K

T2=55+273=328K

By applying the formula, we get:

3.22/313=V2/328

V2=(3.22*328)/313

V2=3.374L

12.5 grams will be left.

Given:

half life of X= 6 days

Initial amount - 50 kg

Amount left after 3 days = ?

Half life - The period of time needed for anything to go through a process in which half of it participates, for example, the period of time needed for half of a radioactive substance's atoms to disintegrate. It means after half life the element will become half its quantity.

A quantity's half-life (symbol - t1/2) is the amount of time needed for it to decrease to half of its initial value. In nuclear physics, the phrase is frequently used to indicate how rapidly unstable atoms decay radioactively or how long stable atoms last.

According to the question, If half life is 6 days and we start with 50 kg of element, after 6 days it will become 25 kg and after 3 days it will become 12.5 grams .

t¹/₂ = 6 days

Initial amount = 50 kg

After half life = 50/2

                     = 25 kg

∴ After 3 days = 25/ 2

                        = 12.5 kg

Hence, 12.5 kg is left after 3 days.

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Answer:

the heat source for our planet is the sun. Energy from the sun is transferred through space and through the earth's atmosphere to the earth's surface. Since this energy warms the earth's surface and atmosphere, some of it is or becomes heat energy.

Answer:

People show more interest in personal broadcasting.

Explanation:

The art of oration (speaking) is being  replaced by personal broadcasting mean now people used webcam or camcorder for creating its own content and transmit it to other people through internet. Personal broadcasting provides audio and video to the individual that make it more interesting as compared to oration. People show more interest in personal broadcasting as compared to oration so that's why oration is replaced by personal broadcasting.

First, we define density as:

Density = mass/volume;

We focus first on the volume of air in the room.

Volume:

We have the measurements of where the air is.

We calculate the volume with these measurements, but first, we change the units to L:

1 inch = 2.54 cm

1 L = 10^3 cm^3

1 ft = 12 inch

Now,

11.0 ft x (12 in/1 ft) x (2.54 cm/1 in) = 335.28 cm

12.0 ft = 365.76 cm

10.0 ft = 304.8 cm

Therefore, the volume of the room = 335.28 cm x 365.76 cm x 304.8 cm

Volume = 37378237.5 cm^3 x (1 L/10^3cm^3) = 374 x 10^2 L

From the Density equation, we clear the mass:

Density x volume = mass (g)

1.19 g/L x 374x10^2 L = 445x10^2 g x (1 kg/1000 g) = 44.5 kg

Answer: 44.5 kg

To determine the volume of N2(g) produced by the complete decomposition of 1 mole of nitroglycerin (C3H5N3O9), we need to consider the balanced chemical equation for the decomposition reaction.

The balanced equation for the decomposition of nitroglycerin is as follows:

4 C3H5N3O9(s) → 12 CO2(g) + 10 H2O(g) + 6 N2(g) + O2(g) From the balanced equation, we can see that for every 4 moles of nitroglycerin, 6 moles of N2(g) are produced. Since we are considering the decomposition of 1 mole of nitroglycerin, we can use this ratio to determine the moles of N2(g) produced, which is 6/4 = 1.5 moles of N2(g). Now, at STP (Standard Temperature and Pressure), 1 mole of any ideal gas occupies 22.4 liters. Therefore, 1.5 moles of N2(g) would occupy approximately 33.6 liters

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The empirical formula of a sample of a compound that contains 72.0 g of C. 18.0 g of H, and 28.0 g of N is C₃H₉N.

Empirical formula is the notation indicating the ratios of the various elements present in a compound, without regard to the actual numbers.

The empirical formula of a compound can be calculated as follows:

C = 72.0g

H = 18.0g

N = 28.0g

Next, we divide by the atomic mass of each element as follows:

Next, we divide by the smallest mole as follows:

The empirical ratio is 3:9:1, hence, the empirical formula of the compound is C₃H₉N.

The options to the incomplete question are as follows:

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Answer:

so wat is it in?.....????

1. too

2. for

3. ate

4.for teen

5. suck`s teen

did i get it right?

Answer:

B 16

Explanation:

the atomicnumber =protons of the atom =electrons do keep in mind that they are charged negatief

The percent error for the thermometer reading is approximately 1.72%. For the heat of neutralization, the percent error is approximately 4.46%.

The percent error is calculated using the formula:

\(\[\text{{Percent Error}} = \left|\frac{{\text{{Experimental Value}} - \text{{Accepted Value}}}}{{\text{{Accepted Value}}}}\right| \times 100\%\]\)

For the thermometer reading, the experimental value is 76.25 °C and the accepted value is 74.96 °C. Plugging these values into the formula, we get:

\(\[\text{{Percent Error}} = \left|\frac{{76.25 - 74.96}}{{74.96}}\right| \times 100\% \approx 1.72\%\]\)

For the heat of neutralization, the experimental value is -58.7 kJ/mol and the accepted value is -56.2 kJ/mol. Plugging these values into the formula, we get:

\(\[\text{{Percent Error}} = \left|\frac{{-58.7 - (-56.2)}}{{-56.2}}\right| \times 100\% \approx 4.46\%\]\)

The percent error provides a measure of the deviation between the experimental and accepted values, expressed as a percentage. In both cases, a positive percent error indicates that the experimental value is higher than the accepted value, while a negative percent error indicates that the experimental value is lower. The percent error allows for comparison and evaluation of the accuracy of measurements or experimental results.

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Answer:

the answer is 7.67

Explanation:

hljkdhfjkdsfh

The name of the organic compound is 2-methyl pentane. The given organic compound is a five-carbon system with a substitution at the C-2 carbon. The naming of an organic compound is done according to the rules given by IUPAC.

The given organic compound has 5 carbon in its main chain. So It has the root word Pent. Since, all the bonds are single bonds, the organic compound is saturated, hence it has the suffix -ane. Hence the unsubstituted straight chain is pentane.

Numbering is done from right to left, because when the numbering is from right to left, the substituted carbon gets C-2, when it is numbered from left to right, the substituted carbon gets C-4. So the numbering is from the right and the substituted carbon is C-2. The substituent is a single carbon system, a methyl substituent. So the organic compound is named 2-methyl pentane .

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Answer:

Viscosity is the measure of how much something can flow.

Explanation:

For example Honey is high in viscosity because it does not flow well. But water on the other hand is low in viscosity because it flows well

The true statement of a molecule of gaseous hydrogen is It has no net charge. Therefore the correct option is option A.

A covalently bound pair of hydrogen atoms make up a gaseous hydrogen molecule (H2), which is a substance. This indicates that in order to create a stable molecule, the two hydrogen atoms share an electron.

H2 is the lightest and most prevalent element in the universe and is a diatomic gas at room temperature and atmospheric pressure. It has no colour, no smell, and is non-toxic.

Highly flammable H2 gas can be used as fuel for a variety of devices, including fuel cells, IC engines, and rockets. Another way to create H2 gas is through the electrolysis of water, reforming of natural gas, or gasification of coal. Therefore the correct option is option A.

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The following question may be like this:

What is true of a molecule of gaseous hydrogen (H2)? Multiple choice question.

Explanation

To find the molar mass of K2Cr2O7 are needed the atomic masses of each element that the molecule contains.

(Please, the periodic table is useful)

The atomic masses:

K) 39.0

Cr) 52.0

O) 16.0

-------

The molar mass = 2 x 39.0 (K) + 2 x 52.0 (Cr) + 7 x 16.0 (O) = 294 g/mol

Answer: A. 294 g/mol

Answer:

1.Frequency

2.Amplitude

3.Wavelength

4.Medium

5.Back and Forth

6.Up and Down

Explanation:

CORRECT ME IF I'm wrong

0.198 grams of KOH are required to neutralize 14.7 mL of 0.12 M HCl stomach acid.

To find out how many grams of KOH are required to neutralize 14.7 mL of 0.12 M HCl stomach acid, we need to use the following formula:

Molarity × Volume = moles

To determine the grams of KOH required, we can use the following steps:

Step 1: Calculate the number of moles of HCl used

Molarity = (number of moles) / (volume in liters)

0.12 M = (number of moles) / (0.0147 L)

Number of moles of HCl used = 0.12 × 0.0147 = 0.001764 moles

Step 2: Determine the balanced chemical equation

\(2KOH + H_2SO_4\) ⇒ \(K_2SO_4 + 2H_2O\)

The stoichiometric ratio of HCl to KOH is 1:2 (based on the balanced chemical equation above).

Step 3: Determine the number of moles of KOH required

Number of moles of KOH required = 0.001764 moles

HCl × (2 moles KOH / 1 mole HCl) = 0.00353 moles KOH

Step 4: Calculate the grams of KOH required

Grams of KOH required = (number of moles KOH) × (molar mass of KOH)

Grams of KOH required = 0.00353 moles

KOH × 56.11 g/mol (molar mass of KOH) = 0.198 g KOH

Therefore, 0.198 grams of KOH are required to neutralize 14.7 mL of 0.12 M HCl stomach acid.

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Answer:

Ice is a molecular and crystalline solid.

Explanation:

Water freezes at 0 degrees Celsius; it has strong molecular bonds between the hydrogen and oxygen atoms of each molecule, and weaker intermolecular bonds between each molecule of water. The polarity of the molecules helps align them into an organized, repeating patterned, crystalline structure when a solid.

Answer:

B . Carbon hydrogen oxygen

Explanation:

I'll hope work it

Explanation:

Because chemistry deals with the structure of matter (such as the structure of the atom, it is related to physics. ... Because geology involves study of the matter the Earth and other bodies in the solar system are made of, geology involves chemistry. Geochemistry is the study of Earth materials, and how they change.

Answer: 0.151 M

Explanation:

We first need to convert the amount of KCl into moles. This is 8.45/74.55 = 0.113 moles.

So, the molarity is 0.113/0.750 = 0.151 M

The most accurate value for the boiling point of water is about 102°.

The term accuracy refers to the fact that the value is close to the accepted or the true value. The term precision refers to how closely bound together the values in a replicate measurement are.

Having said that, we can see that the most accurate value for the boiling point of water is about 102°. In the case of second question, the table is not shown hence the question can not be answered.

For the third question, we know that the value of the load that the roller coaster can carry is 1686.5 kg, when the sign says that the roller coaster can carry as much as 1700 kg, the roller coaster could become overloaded and become harder to move.

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The correct answer is

E) F2 can be classified as a weak electrolyte

The atomic number of fluorine is nine, and its chemical symbol is F. It is the palest halogen and is normally an exceedingly deadly pale yellow diatomic gas. It is the most electronegative reactive element and is extremely reactive, interacting with all other elements except for light inert gases.Fluorine atoms have nine electrons, one fewer than neon, and their electron configuration is 1s22s22p5—two in a full inner shell and seven in an empty outer shell. The physical properties of the atom are affected by the large effective nuclear charge (9 2 = 7) and insufficient nuclear shielding of the outer electrons.

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