How and why was the periodic table set up?

Answer:

Explanation:

Ionic compounds are electrically neutral because the charges of the cations and anions that make up the compound cancel each other out. In the case of salt for example, sodium has a charge of positive one, and chloride has a charge of negative one. Together, they neutralize the compound.

Answer:

The Second Law of Thermodynamics poses an insurmountable problem for ... More time will make things worse for the Darwinist, not better. ... error fail-safe and proof-reading devices utilized for quality control, assembly ... No one really supports the idea that the sun + non life = life

Explanation:

According to the second law of thermodynamics, the energy of the universe is conserved but the entropy of the universe is continuously increasing.

The second law of thermodynamics put some restrictions on the direction of heat transfer and attainable efficiencies of heat engines. This law stated that any spontaneously happening process will lead to an escalation in the entropy (S) of the universe.

This law explains that the entropy of an isolated system will never decrease with time. Mathematically, the 2nd law of thermodynamics:

ΔS (universe) > 0

where ΔS of the universe is the change in the entropy of the universe.

The second law of thermodynamics provides the criterion for the feasibility of any physical or chemical process. A physical or chemical process cannot take place unless it must follow both the 1st and 2nd laws of thermodynamics.

Learn more about second law of thermodynamics, here:

https://brainly.com/question/1604031

#SPJ2

Answer:

Concentration of dissolved salts = 34,038.76 ppm

Explanation:

Given:

Salinity of ocean water = 34

Find:

Concentration of dissolved salts

Computation:

Salinity of ocean water = 34 g/l

1g/l = 1001.14 ppm

Concentration of dissolved salts = 1001.14 ppm x 34

Concentration of dissolved salts = 34,038.76 ppm

Answer:

opposite

Explanation:

Answer:

opposite

Explanation:

cu9c9ucoucucpucfpufupfpucupvpjvpucu

Two atoms that are different isotopes of the same element have same number of protons.

Element is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.

Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.

The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.Each element has atoms which are unique to itself.

Learn more about elements,here:

https://brainly.com/question/1812430

#SPJ2

Answer:

Well I think that the frogs ability to breath underwater is a adaptation to help them from prededors. Also, they have camophlage to help too.

Answer:

Pb²⁺(aq) --> Ni²⁺(aq)

Explanation:

The equation of the reaction is given as;

Ni(s) + Pb(NO₃)₂(aq) --> Pb(s) + Ni(NO₃)₂(aq)

In writing the ionic equation, we break the aqueous compound into ions. The solid and liquid compounds are ignored.

We have;

Pb²⁺(aq)  + NO₃²⁻(aq) -->  Ni²⁺(aq)  + NO₃²⁻(aq)

Canceling the spectator ions;

Pb²⁺(aq) --> Ni²⁺(aq)

Answer:

Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)

Explanation:

The complete ionic equation of this reaction is

Ni(s)+Pb2+(aq)+2 NO−3(aq)→Ni2+(aq)+2 NO−3(aq)+Pb(s)

The nitrate ions are spectator ions and can be removed from the equation, giving us

Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)

Answer:

Yes

Explanation:

Answer:

Well the answer of 1 and 3 is WRONG based on the 1 star review and the answer of 3 is wrong too I just took a test with this question.

Explanation:

Sorry...

Answer:

it's 6

Explanation:

I just took the test and got it right

Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\ [/tex]

From the question we have

[tex]volume = \frac{65}{5.45} \\ = 11.926605...[/tex]

We have the final answer as

Hope this helps you

Answer:

68.48%

Explanation:

The percent mass of an element in a compound tells us about the amount of such element contributed to the total compound.

In this case, 7.28 g sample of chromium metal was heated to produce chromium oxide with weight of 10.63 g. The percent mass of chromium in chromium oxide can be calculated by using the formula:

%mass of Cr = mass of Cr/mass of Chromium oxide × 100%

%mass of Cr = 7.28/10.63 × 100

%mass of Cr = 0.6848 × 100

%mass of Cr = 68.48%

Answer:

D

Explanation:

Light blubs are not made of fire.

The sun wasnt made by humans.

You cant find Light bulbs in nature.

Meaning it is D.

Answer: c

because gasses are less dense than liquids

Answer:Glucose, Oxygen and Water

Explanation:

Answer:

Hello i have don this... : )

Explanation:

It is oxygen and glucose

Have a good day im 100% sure this is... i forgot but it is before or after the asexual and sexual lessons

I added a meme for no reason you will only get it if you have read heroes of Olympus

Answer:A

Explanation:

Answer:

Aluminium is in period number 3

The aluminum is placed in period 3 of the periodic table.

Periods are the seven horizontal rows that make up the periodic table. Periods are the horizontal rows in the periodic table. Each period represents the consecutive occupation of orbitals in an atom's valence shell, also with long periods representing the occupation of orbitals in a d subshell.

The periodic table could be thought of as a visualization of the elements, from which it is simple to determine the physical and chemical properties of any given element.

It is given that, electronic configuration of aluminum is [tex][Ne]3s^{2},3p^{1}[/tex].

It can be seen that last electrons enter in 3p orbital , here 3 tells about the period of the element where it will be placed in periodic table.

Therefore, aluminum will be placed in period 3.

To know more about period and periodic table.

https://brainly.com/question/11155928

#SPJ2

Answer:

[tex]V=247L[/tex]

Explanation:

Hello there!

In this case, since the density is defined as the degree of compactness of a substance and is computed by diving the mass over the volume it occupies:

[tex]\rho =\frac{m}{V}[/tex]

Given the density and the mass of the neon, we can compute its density as shown below:

[tex]V=\frac{m}{\rho} =\frac{222g}{0.900g/L}\\\\V=247L[/tex]

Best regards!

The volume of neon in liters is 246.67 L.

To calculate the volume of neon, we use the formula below.

Formula:

Where:

make V the subject of the equation.

From the question,

Given:

Substitute these values into equation 2

Hence, The volume of neon in liters is 246.67 L.

Learn more about volume here: https://brainly.com/question/12410983

Answer: b

Explanation:

Answer:

14

Explanation:

70g/(35mL-30mL)=14g/mL

If a rock with a mass of 70 grams is dropped into a graduated cylinder with 30 milliliter of water in it. The water level rose to 35 milliliters, then the density of the rock in gram / milliliter would be  14  gram / milliliter.

It can be defined as the mass of any object or body per unit volume of the particular object or body. Generally, it is expressed as in gram per cm³ or kilogram per meter³.

The mass of ṭhe rock = 70 grams

The volume of the rock = 35 milliliters - 30 milliliters

                                       = 5 milliliters

The density of the rock = mass of the rock / volume of the rock

                                       =70 grams / 5 milliliters

                                       = 14  gram / milliliter

Thus, the density of the rock would be 14 gram / milliliter.

To learn more about density from here, refer to the link;

brainly.com/question/15164682

#SPJ2

Answer:

forensic scientist

Explanation:

forensic science is the discipline in which professionals use scientific means to analyze physical crime evidence. this evidence is then presented in court in order to help determine the innocence or guilt of a specific suspect.

Answer:

Its a forensic scientist :D

Explanation:

I took a test and got it wrong but it showed the right answer and its a forensic scientist

(don't ask how i got it wrong i was rushing!!)

Hi , I’m really sorry because I just have the first question... so here it is :

So it is 0.52 mol .

Have a nice day .

ANSWER:

2.65 g H2O

Explanation:

6.49g (co2) / 44.009g (co2)  x  1 mol (co2) / 1 mol (h2o)  x 1 mol (h2o)    

=0.147 mol H2O

0.147 mol (H2O) / 1 mol (h2o) x 18.015 g (h2o)

=2.65 g H2O

Answer:

The answer is A

Explanation:

I am Mr. Know It All

Answer:

[N₂O₄] = 0.00411 M

[NO₂] = 0.0918 M

Explanation:

In the reaction of: N₂O₄(g) ⇌ 2 NO₂(g) If the equilibrium constant is Kc = 0.513 and the initial concentration of N₂O₄ = 0.0500 M. What are the equilibrium concentrations of N₂O₄ and NO₂ under these conditions?

Step 1: Given data

Initial concentration of N₂O₄: 0.0500 M

Equilibrium constant (Kc): 0.513

Step 2: Make an ICE chart

        N₂O₄(g) ⇌ 2 NO₂(g)

I        0.0500           0

C           -x              +2x

E      0.0500-x        2x

Step 3: Find the value of "x"

The equilibrium constant is:

Kc = [NO₂]² / [N₂O₄]

0.513 = (2x)² / (0.0500-x)

4x² + 0.513 x -0.02565

We solve for x and we get x₁ = 0.0458942 and x₂ = −0.558894 (neglected).

Step 4: Calculate the concentrations at equilibrium

[N₂O₄] = 0.0500-x = 0.00411 M

[NO₂] = 2x = 0.0918 M

Answer:

..............what.......