Answer fast my H.W is hard

Answer:

Solution :

Lithium

Z = 3

P = 3

E = 3 = (2, 1) p=3

A = 7 n=4

P + n = A

3 + n = 7

N = 4



Carbon

Z = 6

P = 6

E = 6 = (2, 4) p=6

A = 12 n=6

P + n = A

6 + n = 12

N = 6

Answer:

The amount of heat required is 4681.6 J.

Explanation:

mass, m = 16 g = 0.016 kg

initial temperature, T = 5 C

final temperature, T' = 75 C

specific heat, c = 4.18 J/g C

The amount of heat required is

H = m c (T'- T)

H = 16 x 4.18 x (75 - 5)

H = 4681.6 J

Answer:

For 2: The % yield of the product is 92.34 %

For 3: 12.208 L of carbon dioxide will be formed.

Explanation:

The percent yield of a reaction is calculated by using an equation:

[tex]\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100[/tex]              ......(1)

Given values:

Actual value of the product = 78.4 g

Theoretical value of the product = 84.9 g

Plugging values in equation 1:

[tex]\% \text{yield}=\frac{78.4 g}{84.9g}\times 100\\\\\% \text{yield}=92.34\%[/tex]

Hence, the % yield of the product is 92.34 %

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(2)

Given mass of carbon dioxide = 24 g

Molar mass of carbon dioxide = 44 g/mol

Plugging values in equation 1:

[tex]\text{Moles of carbon dioxide}=\frac{24g}{44g/mol}=0.545 mol[/tex]

At STP conditions:

1 mole of a gas occupies 22.4 L of volume

So, 0.545 moles of carbon dioxide will occupy = [tex]\frac{22.4L}{1mol}\times 0.545mol=12.208L[/tex] of volume

Hence, 12.208 L of carbon dioxide will be formed.

Answer:

[tex] \small \sf \fbox{Physical Change}[/tex]

Explanation:

Crushing a mineral into powder is a physical change.

Answer:

Antoine Lavoisier and Johann Wolfang Döbereiner organized the elements based on properties such as how the elements reacts or whether they are solid or liquid.

Explanation:

The periodic table of the elements as we have it today was developed as a result of the work of several notable centuries who lived centuries apart, all of who made notable contributions to development of the modern periodic table in use today.

In 1789, Antoine Lavoisier, a French Chemist provided a definition of elemets which he defined as a substance whose smallest units cannot be broken down into a simpler substance. He further grouped the elements into two as metals and nonmetals.

In 1829, German physicist Johann Wolfang Döbereiner arranged elements in groups of three in increasing order of atomic weight and called them triads. His arrangement owasf elements into triads was based on his observation of similarities in physical and chemical properties of certain elements.

John Newlands, a British Chemist was the first to arrange the elements into a periodic table with increasing order of atomic masses.

In 1869, Russian chemist Dmitri Mendeleev developed a periodic table which provided a framework the modern periodic table. He arranged the elements according to their atomic weight, leaving gaps for elements that were yet to be discovered.

The modern periodic table arranges elements based on increasing atomic number.

Answer:

That is, a pH meter is useful in detecting or knowing the acidity (due to ions) or alkalinity (due to ions) of a solution. Thus, we can conclude that out of the given options it is true about a pH meter that it can be used in any acid-base titration

Answer: D. It can be used in any acid-base titration.

Explanation:

Answer:

B

Explanation:

)When iron rusts in air, iron(III) oxide is produced. How many moles of oxygen will react

with 2.4 mol of iron ?

B)1.8 mol

Answer:

I think no. 4

Explanation:

It is true that Earth’s orbit is not a perfect circle. It is slightly elongated, so that during part of the year, Earth is closer to the Sun than at other times. However, in the Northern Hemisphere, we are having winter when Earth is closest to the Sun and summer when it is farthest away!

There is a completely different reason for Earth's seasons.

Earth's axis is an imaginary pole going right through the center of Earth from "top" to "bottom." Earth spins around this pole, making one complete turn each day. That is why we have day and night, and why every part of Earth's surface gets some of each.

Earth has seasons because its axis doesn't stand up straight

(to be clear I just copied it from some resources)

Answer:

25 possibly

Explanation:

I'm not too sure about this, but sodium oxide is Na2O, 2 sodium and 1 oxygen, so 12.5g * 2 is 25

If someone else comes up with a more convincing argument listen to them

Answer:

H2 and O2

Explanation:

A coffee cup calorimeter is basically a type of calorimeter that operates at constant pressure. The heat measured in the calorimeter is equal to the change in enthalpy of the reaction.

This type of calorimeter is apt for reactions involving solutions where there is little or no change in volume.

It is not generally applicable to gas phase reactions such as the reaction between H2 and O2.

Answer:

You will not measure the enthalpy of the reaction of

✔ H2 and O2

in the coffee cup calorimeter because this reaction involves gases. Instead, you will use a well-known published value.

C. H2 and O2

Is Correct

Answer: Atoms with 11 protons, 10 neutrons and 11 electrons belong to the same element with 11 protons, 12 neutrons and 11 electrons.

Explanation:

Elements that contain same number of valence electrons belong to the same group. This is because they will have same reactivity (or properties) due to which they lie in the same group.

For example, element with 11 protons, 10 neutrons and 11 electrons is same as the element with 11 protons, 12 neutrons and 11 electrons.

Hence, both these atoms belong to the same element.

Thus, we can conclude that atoms with 11 protons, 10 neutrons and 11 electrons belong to the same element with 11 protons, 12 neutrons and 11 electrons.

#CarryOnLearning

The chemical properties of an element are determined by which particle of an atom?

[tex]\longrightarrow{\green{c.\:proton}}[/tex] 

Explanation:

The chemical properties of an element are determined by the subatomic particle known as a proton. The number of protons in an atom is called its atomic number ( Z ).

[tex]\large\mathfrak{{\pmb{\underline{\orange{Mystique35 }}{\orange{♡}}}}}[/tex]

Answer:

A

Explanation:

Answer:

The volume of 55 grams of BF₃ is 18.1664 L.

Explanation:

If the molar mass of compound BF₃ is 67.81 [tex]\frac{grams}{mole}[/tex], then the number of moles 55 grams of compound contains is calculated as:

[tex]55 grams* \frac{1 mole}{67.81 grams} = 0.811 moles[/tex]

The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.

Then it is possible to apply the following rule of three: if by definition of STP 1 mole of a compound occupies 22.4 L, 0.811 moles of the compound occupies how much volume?

[tex]volume=\frac{0.811 moles* 22.4 L}{1 mole}[/tex]

volume= 18.1664 L

The volume of 55 grams of BF₃ is 18.1664 L.

Answer:

Explanation:

1 mole of helium gas contains 6.02 x10^23 helium atoms. So multiply this by 3 after solving the equation.

Answer:

37800KJ

Explanation:

Answer: The correct option is C) decomposition

Explanation:

Single displacement reaction is defined as the reaction where a more reactive element displaces a less reactive element from its salt solution.

[tex]AX+B\rightarrow BX+A[/tex]

Element B is more reactive than element A

Double displacement reaction is defined as the reaction where an exchange of ions takes place in a solution

[tex]AX+BY\rightarrow AY+BX[/tex]

Decomposition reaction is defined as the reaction where a single large chemical species breaks down into two or more smaller chemical species.

[tex]AB\rightarrow A+B[/tex]

Synthesis reaction is defined as the reaction where two or more smaller chemical species combine together in their elemental state to form a single large chemical species.

[tex]A+B\rightarrow AB[/tex]

For the given chemical reaction:

[tex]2H_2O(l)\rightarrow 2H_2(g)+O_2(g)[/tex]

Here, water is breaking down into two smaller species of oxygen and hydrogen gas. Thus, it is a decomposition reaction.

Hence, the correct option is C) decomposition

Answer:

Decomposition

Explanation:

Answer:

Loss of biodiversity in the wetlands.

Explanation: Pollution can be defined as the emission of toxic, poisonous and harmful chemical substances which are capable of causing environmental degradation and contamination.

Nitrogen pollution enters Earth’s freshwater resources from a variety of human activities, including the use of fertilizers and pesticides in agriculture. This nitrogen pollution has a negative effect on plants and animals living in fresh water. Certain wetland plants, however, are able to purify the water and restore it to its non-polluted state.

Hence, what would most likely increase the negative effects of nitrogen pollution is a loss of biodiversity in the wetlands i.e the various species of animal and plants.

Answer:Electronegativity, symbolized as χ, is the tendency of an atom to attract shared electrons (or electron density) to itself.    

Explanation:

Answer:

Explanation:

The correct answer is cesium

Because If you look at the electronegativities of just Lithium and Cesium then you would notice that the shielding effect is more prevalent in Cesium, thereby reducing the electronegativity and affecting the reduction potential

Answer:

Acids react with most metals to form a salt and hydrogen gas. As discussed previously, metals that are more active than acids can undergo a single displacement reaction. For example, zinc metal reacts with hydrochloric acid, producing zinc chloride and hydrogen gas.

Explanation:

Answer:

It has a greater concentration of hydroxide ion than hydronium ions.

Answer:

C this is C.Sea breeze according to the photo.

Answer:

I think its "sunspots"

Explanation: