Can someone please help me. Like right now please

Answer:

Helium (He)

Lithium (Li)

Beryllium (Be)

Boron (B)

Explanation:

The chemical elements which have two (2) electron shells are: Lithium and Boron.

Valence electrons can be defined as the number of electrons present in the outermost electron shell of an atom. Thus, valence electrons is typically used to determine whether or not an atom or group of chemical elements found in a periodic table can form a chemical bond with others.

This ultimately implies that, valency is a property that is typically used in determining the chemical properties of chemical elements.  

An electron shell can be defined as the outermost shell of an atom around the atomic nucleus. Thus, it is considered to be an orbit accompanied by electrons around the nucleus of an atom.

In Chemistry, the chemical elements which have two (2) electron shells are:

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Answer:

The angle of incoming sunlight varies at different places

Answer: This answer is multiple choices.

1. Land and water have different heat capacities.

And

3. The angle of incoming sunlight varies at different places.

Explanation: I kept seeing other people only putting in one answer, so I used this answer from someone else. Credit to them!

Answer:

B

Explanation:

Answer:

Graphite

Graphite is a non-metal and it is the only non-metal that can conduct electricity. You can find non-metals on the right side of the periodic table and graphite is the only non-metal that is a good conductor of electricity.

Answer:

Graphite is a non metal which is a good conductor of heat and electricity .

hope it is helpful to you

Option D I got it right

ANSWER: C (ENERGY WAS RELEASED WHEN THE MOLECULE WAS FORMED FROM ITS ELEMENTS.)

HOPE THE OTHER PERSON IS WRONG!

Answer:

⁶¹₂₉Cu + ⁴₂He --->⁶⁵₃₁Ga

Explanation:

Nuclear reactions are reactions which occur with changes in the nucleus of an atom. Nuclear reactions usually occur with the release of large amounts of energy and radiation. Radiactive elements are elements that are involved in nuclearbreactions due to the unstable nature of their nucleus. They disintegrate spontaneously with the emission of radiations. The major types of radiations released during nuclear reactions are;

1, Alpha particles - these are positively charged radiations with strong ionizing power. Each alpha particle is a helium nucleus

2. Beta particles - these are very fast moving stream of electrons. They are negatively charged particles .

3. Gamma radiation - is a form of electromagnetic radiation.

In the alpha absorption of Cu-61, the proton number of the atom increases by 2 while the mass number increases by 4 and the Cu-61 atom is changed to Ga-65 atom. The nuclear equation is given as follows:

⁶¹₂₉Cu + ⁴₂He --->⁶⁵₃₁Ga

Answer:

7.35 *2

Explanation:

Because I mole of Na2o is made of 2 moles of NaOH

Answer: sun is directly over the equator

Explanation:

There are only two times of the year when the Earth's axis is tilted neither toward nor away from the sun, resulting in a "nearly" equal amount of daylight and darkness at all latitudes.

Answer:

Adding an acid increases the concentration of H3O+ ions in the solution. Adding a base decreases the concentration of H3O+ ions in the solution. An acid and a base are like chemical opposites. If a base is added to an acidic solution, the solution becomes less acidic and moves toward the middle of the pH scale.

Answer:

587.5 L (Option A)

Explanation:

The reaction is:

2 C₈H₁₈ + 25O₂  → 16CO₂  + 18H₂O

We know that in STP conditions 1 mol of any gas is contained in 22.4L

Then, we can make a rule of three, to determine the moles of produced carbon dioxide.

22.4L is the volume for 1 mol

376 L will be the volume for  (376 . 1) 22.4 = 16.78 moles at STP conditions.

Stoichiometry is 16:25.

16 moles of CO₂ are produce by the reaction of 25 moles of O₂

Then, 16.78 moles of CO₂ were produced by (16.78 . 25) /16 = 26.2 moles.

Now, the rule of three again.

1 mol of oxygen gas is contained at 22.4L, at STP conditions

26.2 moles might be contained at (26.2 . 22.4)/1 = 587.5 L

Answer:

Option D

Explanation:

Hydronium ion concentration is a measure of pH of a solution.

The mathematical equation for the same is [H3O+] = 10-pH

OR

[H3O+] = antilog (- pH)

Hence, option D is correct

Answer:

density.

Explanation:

A cubic centimeter of water weighs 1 gram. Since a cubic centimeter of vegetable oil weighs less than 1 gram, oil will float on water. Corn syrup is more dense than water so 1 cubic centimeter of corn syrup weighs more than 1 gram. Therefore, corn syrup sinks in water.

Answer:

Click on the photo to see the full attachment

Answer:Sublimation is the conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage. For those of us interested in the water cycle, sublimation is most often used to describe the process of snow and ice changing into water vapor in the air without first melting into water.

Explanation:

Answer:

The correct response is "9.313 M".

Explanation:

According to the question, the values are:

Moles of solute,

= 0.57 moles

Liters of solution,

=  61.2 mL

or,

= 0.0612 L

Now,

The molarity will be:

= [tex]\frac{Moles \ of \ solute}{Liters \ of \ solution}[/tex]

On putting the given the values in the above formula, we get

= [tex]\frac{0.57}{0.0612}[/tex]

= [tex]9.313 \ M[/tex]

H2CO3 + NaOH --> Na2CO3 + H2O

Here salt is Na2CO3.

So, (A) H2O + Na2CO3 is your answer.

Answer:

The right solution is "0.7107 J/g°C".

Explanation:

The given values are:

Mass,

m = 4.11 g

Temperature,

ΔT = 3.8°C

Heat,

Q = 11.1 J

The specific heat of silicon will be:

⇒  [tex]C=\frac{Q}{m \Delta T}[/tex]

On substituting the values, we get

⇒      [tex]=\frac{11.1}{4.11\times 3.8}[/tex]

⇒      [tex]=\frac{11.1}{15.618}[/tex]

⇒      [tex]=0.7107 \ J/g^{\circ}C[/tex]

A covalent compound is a compound with a metal and a nonmetal ion sharing valence electrons (option A).

A covalent compound is a molecule formed by covalent bonds, in which the atoms share one or more pairs of valence electrons.

Covalent bond is a type of chemical bond where two atoms are connected to each other by the sharing of two or more electrons.

Chemical compounds are generally grouped into one of two categories as follows;

Covalent or molecular compounds generally result from two nonmetals reacting with each other. The elements form a compound by sharing electrons, resulting in an electrically neutral molecule.

Examples of covalent compounds are as follows:

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Answer: The temperature at pressure of 635.7 kPa is [tex]2033^0C[/tex]

Explanation:

The combined gas equation is,

[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]

where,

[tex]P_1[/tex] = initial pressure of gas = 107.4 kPa

[tex]P_2[/tex] = final pressure of gas = 635.7 kPa

[tex]V_1[/tex] = initial volume of gas = [tex]515cm^3[/tex]

[tex]V_2[/tex] = final volume of gas = [tex]644cm^3[/tex]

[tex]T_1[/tex] = initial temperature of gas = [tex]38.6^0C=(38.6+273)K=311.6K[/tex]

= final temperature of gas = ?

Now put all the given values in the above equation, we get:

[tex]\frac{107.4\times 515}{311.6}=\frac{635.7\times 644}{T_2}[/tex]

[tex]T_2=2306K=(2306-273)^0C=2033^0C[/tex]

The temperature at pressure of 635.7 kPa is  [tex]2033^0C[/tex]

The statement that best describes a chemical property related to the particles that make up a material is A) nickel is a good conductor of electricity because the metallic bonds between its atoms allow electrons to move freely. Option A

Chemical properties describe how substances undergo chemical reactions or interactions with other substances. In this case, the statement about nickel highlights a specific chemical property related to its ability to conduct electricity.

Nickel is a metallic element with a unique atomic structure. It possesses metallic bonds, which involve the sharing of electrons between atoms within a metal lattice. In metallic bonding, the valence electrons of metal atoms are delocalized, meaning they are not strongly associated with any specific atom but are free to move throughout the material.

The presence of these mobile electrons in nickel enables it to conduct electricity effectively. When a potential difference is applied across a conductor like nickel, the mobile electrons can move in response to the electric field, carrying electrical charge from one point to another.

Option B) is incorrect because hardness is a physical property related to the arrangement and bonding of atoms, not a chemical property.

Option C) is also incorrect because malleability is a physical property resulting from the ability of metal atoms to slide past each other when a force is applied, not a chemical property.

Option D) describes the electronic configuration of chlorine, which is a characteristic of its atom but does not directly relate to a chemical property associated with the particles that make up a material.

In summary, option A best describes a chemical property related to the particles that make up a material, specifically nickel's ability to conduct electricity due to the presence of mobile electrons enabled by metallic bonds.

Option A

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Answer:

B) inertia

Explanation:

Sorry if wrong

Answer:

white precipitate of barium chloride is formed

Answer:

hydroxide is the one because it is the one HAHAH

Answer:

hydroxide, OB

Explanation:

hydroxide,OB

Answer:

please follow me

Explanation:

A displacement reaction is the one when a more reactive substance displaces a less reactive one from its salt solution whereas a double displacement reaction is the one where a mutual exchange of ions happens between two compounds.

Explanation:

As you can that water splits into molecules of hydrogen and 1 molecules of oxygen since , number of molecules of hydrogen released is double the number of molecules of oxygen released, volume occupied by hydrogen gas is double the volume occupied by oxygen gas

Answer:

[tex]Q=-50,307kJ[/tex]

Explanation:

Hello there!

In this case, since following reaction:

C2H4+3 O2-> 2CO2 + 2H2O

Has an enthalpy of combustion of ethene is about -1411.1 kJ/mol (can be found on goo gle), it is possible to calculate the total amount of energy that is released when 1000 grams of ethene are burned as shown below:

[tex]Q=-1411.1 \frac{kJ}{molC_2H_4} *\frac{1molC_2H_4}{28.05gC_2H_4}*1000gC_2H_4 \\\\Q=-50,307kJ[/tex]

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