which of the following elements are more reactive than the others.
A. calcium (Ca)
B. Magnesium (Mg)
C. potassium (K)
D. Sodium (Na) ​

Answer:

Yes.

Explanation:

Yes, enough folic acid in the body by the early weeks of pregnancy helps to prevent spina bifida. The body of woman uses folate during the pregnancy which produces red and white blood cells that help your baby to grow. Folate also lowers the risk of neural tube defect (NTD) in the unborn baby. Neural tube defect (NTDs) are the serious birth defects that greatly affect the spinal cord, brain and skull of the baby.

Answer:

True

Explanation:

Hydrogen bonding is a type of intermolecular interaction that occurs when hydrogen is bonded to a highly electronegative atom.

We define the term ''hydrogen bond donor'' as the molecule that supplies the hydrogen atom in the hydrogen bond.

Hence, it is true that the molecule or ion that donates the hydrogen in a hydrogen bond is a hydrogen bond donor

Answer:

yes

Explanation:

cos of high electron transfer

Answer:

The most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca

Explanation:

The mass, in percentage, of eah isotope of Calcium is their fractional composition multiplied by 100:

40Ca-0.96941*100 =  96.941% of ⁴⁰Ca

42Ca-0.00647*100 = 0.647% of ⁴²Ca

43Ca-0.0013*100 = 0.13% of ⁴³Ca

44Ca-0.02086*100 = 2.086% ⁴⁴Ca

46Ca-0.00004*100 = 0.004% ⁴⁶Ca

48Ca-0.00187*100 = 0.187% of ⁴⁸Ca

That means the most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca

Answer: 26 moles of [tex]PH_3[/tex] are required for the reaction.

Explanation:

We are given:

Moles of [tex]P_4O_{10}[/tex] = 6.5 moles

The given chemical reaction follows:

[tex]4PH_3(g)+8O_2(g)\rightarrow P_4O_{10}(s)+6H_2O(g)[/tex]

By the stoichiometry of the reaction:

If 1 mole of [tex]P_4O_{10}[/tex] is produced by 4 moles of [tex]PH_3[/tex]

So, 6.5 moles of [tex]P_4O_{10}[/tex] will be produced by = [tex]\frac{4}{1}\times 6.5=26mol[/tex] of [tex]PH_3[/tex]

Hence, 26 moles of [tex]PH_3[/tex] are required for the reaction.

Answer:

option b is your right answer

Answer:

Group 1A: alkali metals, or lithium family.

Group 2A: alkaline earth metals, or beryllium family.

Group 7A: the manganese family.

Group 8A: the iron family.

Explanation:

Answer:

1A: Alkali Metals

2A: Alkaline Earth Metals

7A: Halogens

8A: Noble Gases

Answer: See explanation

Explanation:

Vacuum filtration is referred to as a fast filtration technique that is used in the separation of solids from liquids. It is also used to collect a desired solid. It basically uses a side-arm flask and a Buchner funnel.

Based on the question, the techniques that should be used to ensure a quantitative separation goes thus:

• Wet the filter paper before the mixture is poured into the filter funnel.

• Then, carefully rinse the flask with a little amount of water into the filter funnel.

• After that, the solid on the filter paper should be washed the with a small amount of water.

• Finally, Dry the solid on the filter paper when the separation is done.

Answer:

The answer is C... I am almost positive.

Answer:

D. the minerals they contain

Hope this answer is right!!

Answer:

% yield =  82.5%

Explanation:

HgO + 2Cl₂ →  HgCl₂ +  Cl₂O

Our reactants are:

Our products are:

We do not have information about moles of reactants, but we do know the theoretical yield and the grams of product, in this case Cl₂O, we have produced.

Percent yield = (Yield produced / Theoretical yield) . 100

Theoretical yield is the mass of product which is produced by sufficent reactant. We replace data:

% yield = (0.71 g/0.86g) . 100 = 82.5%

The percent % yield =  82.5%

The balanced chemical equation will be:

HgO + 2Cl₂ →  HgCl₂ +  Cl₂O

The reactants participating in this reaction are: HgO and Cl₂

The products so formed are: HgCl₂ +  Cl₂O

[tex]\text{ Percent yield} = \frac{\text{Yield produced}}{\text{Theoretical yield}} *100[/tex]

The theoretical yield is the maximum possible mass of a product that can be made in a chemical reaction.

[tex]\text{Percent yield}= \frac{0.71 g}{0.86g} * 100 \\\\\text{Percent yield}= 82.5\%[/tex]

Thus, the percent yield is 82.5%.

Learn more:

brainly.com/question/25996347

Answer:

B - The high temperature makes the gas molecules spread apart according to Charles's law because this law describes how a gas will behave at constant pressure.

Explanation:

Charle's Law describes the relationship between temperature and volume, where increased temperature leads to increased volume. When volume is increased, that means the gas molecules are more spread apart and have more random motion. Therefore, the answer is B.

The high temperature causes the gas molecules to spread apart according to Charles's law because explain how a gas, behave at constant pressure.

The physical principle called Charles' law which  states that the volume of a gas equals a constant value many by its temperature as measured on the Kelvin scale.

Volume regaled by a clinched amount of gas is directly proportional to its temperature and pressure if remains steady.

Thus, option "B" is correct, the volume of a gas equals a constant value.

To learn more about Charles law click here:

https://brainly.com/question/14842720

Answer:

the Rhyniognatha hirsti

Explanation:

at age 400 million years old

Answer:

Laws governing gas behavior.

Explanation:

Boyle's law:

It relates the pressure and volume of an ideal gas at a constant temperature.

According to this law:

"The volume of a fixed amount of gas at constant temperature is inversely proportional to its pressure".

[tex]P \alpha V[/tex].

Charle's law:

It relates the volume and absolute temperature of an ideal gas at a constant pressure.

According to this law:

"The volume of a fixed amount of gas at constant pressure is directly proportional to its absolute temperature".

[tex]V \alpha T[/tex].

Avogadro's law:

According to this law:

equal volumes of all gases under the same conditions of temperature and pressure contain, an equal number of moles.

[tex]V \alpha n[/tex].

Ideal gas equation:

By combining all the above-stated gas laws, this equation is formed as shown below:

[tex]V \alpha \frac{nT}{P} \\=> V= R. nT/ P\\=>PV=nRT[/tex]

R is called universal gas constant.

It has a value of 0.0821L.atm.mol-1.K-1.

Answer:

Boyle's law, Charle's law,  Guy Lussac's law and Avogadro's law

Explanation:

All the gases behaves similarly when the environment conditions are normal. But when the physical condition changes like when the pressure, volume or temperature changes, the gas behaves differently and shows a deviation.

The number of gas laws are :

Boyle's Law

Boyle's law states that when the temperature remaining constant, the pressure of the gas varies inversely to the volume of the gas.

i.e.   [tex]P \propto \frac{1}{V}[/tex]

Charle' law

Charle's law states that when pressure is constant, the temperature of a gas is directly proportional to the volume.

i.e. , [tex]$T \propto V$[/tex]

Gay Lussac's law

Gay - Lussa law states the volume and the mass of the pressure of the gas is directly proportional to the  temperature of the gas.

i.e. P.T = constant

Avogadro's law

It states that under the conditions of same pressure as well as temperatures, the gases having equal volumes will have same numbers of molecules.

i.e. [tex]\frac{V_1}{n_1}=\frac{V_2}{n_2}[/tex] = constant

Answer:

B. 4 ham slices

Explanation:

A chemical reaction involves one or more substances known as reactants combining chemically to give one or more substances known as products.

Reactants in chemical reactions combine in definite mole or mass ratios to give products. Therefore, when one substance is present in excess of what is required to combine with another to form products, that substance is known as the excess reagent. The other substance which is present in a smaller amount and which when used up, the reaction stops is known as the limiting reagent.

From the illustration of the sandwiches in the question, the recipe for one sandwich represents the chemical equation of a reaction. The equation form is given below:

2 cheese slices + 1 ham slice + 2 bread slices ---> 1 sandwich

The ratio of the reactant is 2 : 1 : 2

From the available ingredients, 12 cheese slices, 10 ham slices, 12 bread slices.

12 cheese slices will require 6 ham slices and 12 bread slices to produce 6 sandwiches.

However, since there are 10 ham slices, 4 ham slices will be left over unused. This is the excess or leftover reactant.

Answer:

B. 4 ham slices

Explanation:

Got it right on the test

Answer:

the answer is H ..............

Answer:

36g

Explanation:

you need to know the equation mass=moles*mr (in this case mr of carbon which is 12)

so 3*12=36g

hope this helps :)

Answer:

95.9 kg

Explanation:

First we convert 15.0 mi² to m²:

Then we convert 27.0 ft to m:

Now we calculate the total volume of the lake:

Converting 3.20x10⁸ m³ to L:

Now we calculate the total mass of mercury in the lake, using the given concentration:

Finally we convert μg to kg:

Answer:

Option 1. NO

Explanation:

The balanced equation for the reaction is given below below:

4NH₃ + 6NO —> 5N₂ + 6H₂O

From the balanced equation above,

4 moles of NH₃ reacted with 6 moles of NO.

Finally, we shall determine the limiting reactant. This can be obtained as follow:

From the balanced equation above,

4 moles of NH₃ reacted with 6 moles of NO.

Therefore, 1.24 moles of NH₃ will react with = (1.24 × 6)/4 = 1.86 moles of NO

From the calculation made above, we can see that a higher amount of NO (i.e 1.86 moles) than what was given (i.e 1.79 moles) is needed to react completely with 1.24 moles of NH₃.

Therefore, NO is the limiting reactant and NH₃ is the excess reactant.

Thus, the 1st option gives the correct answer to the question

Answer:

1. NO .

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to identify the limiting reactant by simply calculating the moles of any product, say N2, via the moles of each reactant and including the corresponding mole ratio (4:5 and 6:5):

[tex]1.24molNH_3*\frac{5molN_2}{4molNH_3}=1.55molN_2 \\\\1.79molNO*\frac{5molN_2}{6molNO}=1.50molN_2[/tex]

Thus, since NO yields the fewest moles of N2 product, we infer it is the limiting reactant.

Regards!

Answer:

1.104 J/g°C

Explanation:

Using Q = m × c × ∆T

Where;

m = mass of substance (g)

c = specific hear capacity (J/g°C)

∆T = change in temperature (°C)

For a colorimeter,

Q(water) = - Q(metal)

m. c. ∆T (water) = - m. c. ∆T (metal)

According to the information provided;

For water:

m = 28.0g

c = 4.184 J/g°C

∆T = (21.23 - 19.73°C)

For the metal:

m = 2.05g

c = ?

∆T = (21.23 - 98.88°C)

m. c. ∆T (water) = - m. c. ∆T (metal)

[28 × 4.184 × (21.23 - 19.73°C)] = -[2.05 × c × (21.23 - 98.88°C)]

[117.152 × 1.5] = -[2.05 × c × (-77.65)]

175.728 = -[-159.1825c]

175.728 = 159.1825c

c = 175.728 ÷ 159.1825

c = 1.104

c = 1.104 J/g°C

Answer:

False

Explanation:

Roman numerals are seen in the names of several compounds. They often appear immediately after the name of central atom in the molecule.

These Roman numerals are used to depict the oxidation state of the central atom in the molecule and not to show how many of that ion appear in the formula.

For instance, in carbon IV oxide, the Roman numeral IV shows that the central atom in the compound-carbon is in the +4 oxidation state.

Answer:

False. Intermolecular forces of attraction are important in holding large molecules together.

Explanation:

Within a molecule, atoms are held together by intramolecular forces. That is, intramolecular forces are the attractive forces that hold the atoms or ions that make up chemical substances (elements and compounds) together, forming a chemical bond.

On the other hand, intermolecular forces are those that act on different molecules or ions and that make them attract or repel each other. In other words, intermolecular forces are those that occur between the different molecules of a compound, and cause these molecules or ions to attract or repel each other.

So, intermolecular forces of attraction are important in holding large molecules together.

Answer:

3.59x10⁻⁴ mol

Explanation:

Assuming ideal behaviour we can solve this problem by using the PV=nRT formula, where:

We input the data given by the problem:

And solve for n:

Answer:

A change is called irreversible if it cannot be changed back again. For example you cannot change a cake back into its ingredients again. Irreversible changes are permanent.

Explanation:

Hope this helps!! :))

Answer:

NaHSO₄(s) --H₂O--> Na⁺(aq) + HSO₄⁻(aq)

Explanation:

Sodium hydrogen sulfate is a strong electrolyte, that is, when dissolved in water it completely dissociates into the cation sodium and the anion hydrogen sulfate. The corresponding chemical equation is:

NaHSO₄(s) --H₂O--> Na⁺(aq) + HSO₄⁻(aq)

Fluids are liquid and gases. They take the shape of their containers. They are called fluids because of their ability to flow.

Answer:

The maximum theoretical percent recovery from the recrystallization of 1.00 g of benzoic acid from 15 mL of water = 94.9%

Note: The question is incomplete. A similar but complete question is given below:

The solubility of benzoic acid in water is 6.80g per 100mL at 100 degrees C and 0.34 g per 100mL at 25 degrees C.

Calculate the maximum theoretical percent recovery from the recrystallization of 1.00 g of benzoic acid from 15 mL of water, assuming the solution is filtered at 25 degrees C.

Explanation:

Solubility of benzoic acid in water at 100 degrees C = 6.80g per 100mL

Solubility of benzoic acid in water  at 25 degrees C =  0.34 g per 100mL

Mass of benzoic acid to be theoretically recovered from 100 mL of water = 6.80 g - 0.34 g = 6.46 g

At 25 degrees;

0.34 g of benzoic acid is present in 100 mL of water

x g of  benzoic acid will be present in 15 mL of water

x = 0.34 × 15 / 100 = 0.051 g

Mass of benzoic acid to be theoretically recovered from 25 mL of water = 1.00 g - 0.051 g = 0.949 g

Maximum theoretical percent recovery = (mass recovered / original mass dissolved) x 100%

Maximum theoretical percent recovery =  (0.949 / 1.00) × 100% = 94.9 %

Therefore, the maximum theoretical percent recovery from the recrystallization of 1.00 g of benzoic acid from 15 mL of water = 94.9%

Explanation:

this explanation may help u to understand:)

Answer:

A

Explanation: