why does the d block start in the fourth row of the periodic table

Answers

Answer 1

Answer:

Why does D-block start on the fourth row of the periodic table?

Explanation:

The require more energy to reach 3d than 4s, and they fill up 4p before 4d, and so forth. ... The energy is lower for 6s than 4f, and 4f and 5f are lower in energy than the final D level.


Related Questions

I need help with this question

Answers

Answer: atomic nucleus

Explanation:

a. What is the mass of 3.47x10^26 molecules of CuCl2?

Answers

Answer:

77460 g

Explanation:

To solve this problem first we convert molecules into moles, using Avogadro's number:

3.47x10²⁶ molecules ÷ 6.023x10²³ molecules/mol = 576.12 moles

Then we convert 576.12 CuCl₂ moles into grams, using its molar mass:

576.12 mol * 134.45 g/mol = 77460 g

So the answer is 77460 g, or 77.46 kg.

balance the word equation then determine the sum of all coefficients.
Gallium metal reacts with chlorine gas to produce gallium chloride. The sum of all coefficients in the balanced equation is ____?

Answers

The sum of all coefficients = 7

Further explanation

Given

The word equation

Required

The sum of all coefficients

Solution

The chemical equation can be expressed in terms of:

word equation skeleton equation balanced equation

Convert the word equation into a chemical equation(skeleton) :

Ga + Cl₂ → GaCl₃

Balanced equation

2Ga + 3Cl₂ → 2GaCl₃

The sum of all coefficients :

= 2+3+2

= 7

Calculate the atomic mass of oxygen if the three common isotopes of oxygen have masses of 15.995 amu (99.759% abundance), 16.995 amu (0.037 % abundance), and 17.999 amu (0.204 % abundance).

Answers

Answer:

16 amu

Explanation:

If the temperature of a gas in a balloon remains constant but the pressure
is decreased, the volume of the balloon will
decrease
increase
remain the same
not enough information to predict

Answers

Answer:

increase

Explanation:

if the pressure goes down then the gas will spread out more, meaning the volume will increase

NEED HELP ASAP WILL GIVE BRAINLYEST Organisms that are made up of prokaryotic cells are NOT ____________. Multicellular All of these are true about prokaryotic cells Simpler than organisms made up of Eukaryotic celled organisms Bacteria

Answers

Explanation:

the answer is that prokaryotic cells are not multicellular

What is the molar mass of Al(NO3)3 · 3H2O?

Answers

Answer:

Go to your periodic table and look for each element. Find the mass for Aluminum, Nitrogen, Oxygen, and Hydrogen.

After you find those, for each compound you must add them together and find the least amount of sig figs after the decimal point.

For the first compound, Al(NO3)3, you will have a total of

1 Aluminum atom

3 Nitrogen atoms

9 Oxygen atoms

Aluminum has 26.982 g/mol

Nitrogen has 14.007 g/mol

Oxygen has 15.999 g/mol

Now multiply those numbers by the amount of atoms of each element.

(1)26.982 g/mol = 26.982 g/mol

(3)14.007 g/mol = 42.021 g/mol

(9)15.999 g/mol = 143.991 g/mol

now add all of those numbers together, and you see that their least significant figure after the decimal is 3, so round to 3 digits after the decimal point.

26.983 + 42.021 + 143.991 = 212.994

now do the same for the other compound

to start you off.. you have

6 Hydrogen atoms

3 Oxygen atoms

Hydrogen has 1.009 g/mol

Oxygen has 15.999 g/mol

the least significant figure after the decimal point is 3, so round you 3 digits after the decimal point.

after you finish getting your totals, you. until them and find the greatest sig fig over all. comment on this if you need further instruction :)

How do the formulas for molecular and ionic compounds differ? Explain the reason for
the difference.

Answers

Answer:

How do the formulas differ for molecular and ionic compounds? The formula for a molecular compound represents the atoms that make up one molecule of a compound. The formula for an ionic compound represents one formula unit of the compound. ... Put two electron between atoms to form a chemical bond.

Explanation:

What happens to a molten ionic substance when an electric current is passed through it

Answers

Answer:

When an electric current is passed through a molten ionic compound the compound decomposes or breaks down. The process also occurs for aqueous solutions of ionic compounds. Liquids and solutions that are able to conduct electricity are called electrolytes

Explanation:

Source: the internet

Brainiest:):):):):):)

Answers

Answer:

1) Condensation

2) Temperature

3) Evaporation

4) Kinetic Energy

5) Sublimation

6) Thermal Energy

Does gases have a kinetic attraction? Yes or no.

Answers

Answer:

No

Explanation:

There are no interactive forces (i.e., attraction or repulsion) between the particles of a gas.

The average kinetic energy of gas particles is proportional to the absolute temperature of the gas, and all gases at the same temperature have the same average kinetic energy.

if you add 5 protons, 4 neutrons, and 3 electrons what is the net charge of the atom

Answers

The answer would be 2 protons because protons are positive and electrons are negative so 5-3=2 and neutrons are neutral they don’t do anything to the charge of the atom

How many grams of Cl2 are needed to produce 2.4 grams of NaCl?
2Na + Cl2 --> 2NaCl

Answers

The answer is 0.017110756386119. We assume you are converting between moles NaCl and gram. You can view more details on each measurement unit: This compound is also known as Sodium Chloride. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles NaCl, or 58.44277 grams.

Hope I helped :)

According to the stoichiometry of the given chemical equation, 1.45 g of Cl₂ are needed to produce 2.4 grams of NaCl.

What is stoichiometry?

Stoichiometry is the determination of proportions of elements or compounds in a chemical reaction. The related relations are based on law of conservation of mass and law of combining weights and volumes.

Stoichiometry is used in quantitative analysis for measuring concentrations of substances present in the sample.

According to the given chemical equation, 70.906 g of chlorine gives 117 g sodium chloride, thus, 2.4 g of sodium chloride will be produced, when 2.4×70.906/117= 1.45 g of Cl₂ reacts.

Thus, according to the stoichiometry of the given chemical equation, 1.45 g of Cl₂ are needed to produce 2.4 grams of NaCl.

Learn more about stoichiometry,here:

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please help this will help my grade a lot

Answers

Answer:

a- customary systems..

True or false; when something heats up, New energy is created, and when something cool down, Energy is destroyed.

Answers

Answer:

This is false.

Explanation:

This statement directly opposes the first law of thermodynamics which states that energy can neither be created nor destroyed, but can transfer from one source to another.

bro needs help

32.5 grams of NaOH reacts with an excess of CO2

2NaOH(s) + CO2(g) ⇒ Na2CO3(s) + H20

What is the theoretical yield of Na2CO3 in grams?

*** I NEED YOU TO SHOW YOUR WORK BROS, I ALREADY HAVE THE ANSWER (43.1g) ***

Answers

i tried and got 6.89g of Na2CO3

lons form when atoms gain or lose valence electrons. When an atom gains
electrons, it becomes negatively charged, and when an atom loses
electrons it becomes positively charged. Why?

Answers

Answer:

In neutral atom number of electrons (negativity charged particle) and number of proton ( positively charged particle) are equal.

When one or more electrons are lost so positive charge particle increases and cation is formed.

For example in Na 11 electrons and 11 protons are present when it loses one electrons protons are 11 and 10 electron are remaining so one positive charge is present.

Morever when an element gain electrons one negative charge increases and anion is formed. For example in Cl 17 proton and 17 electrons are present when it gain one electron 18 electrons and 17 protons are now present one negative is more so anion negative ion is formed.

Explanation:

Which place describes a community?

A. a desert of sand, rock, hawks, and snakes

B. the desert

C. a forest birds, insects, and squirrels

D. a hole in which a snake lives

Answers

answer c because a community is a group of people living in the same place or having a particular characteristic in common

If I have 5 mols of Neon how many grams of Neon do I have?

Answers

Answer:

20.1797 grams.

Explanation:

The molecular formula for Neon is Ne. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Neon, or 20.1797 grams.

What are the steps needed to calculate the percent composition of Carbon in CH4

Answers

CH4 : Mr. 12+(1x4) =16
C= 12
12/16 x 100 =75%

What are the parts of the cell theory?Mark all that apply

Answers

Answer:

Cell theory states that cell living organisms are composed of at least one cell, which are the basic unit of life. Cells are always produced from other living cells, and cannot spontaneously generate

How many moles of S2 are needed to produce 1.50 moles of SO2 gas

Answers

Answer:

1.5moles of S;

Explanation:

The reaction expression is given as:

            S +  O₂   →   SO₂

Number of moles of SO₂  = 1.5moles

From the balanced reaction expression:

              1 mole of SO₂ will be produced from 1 mole of S;

  So;      1.5moles of SO₂  will produce 1.5moles of S;

 

 

The moles of S₂ needed to produce 1.50 moles of SO₂ gas is 1.5 mol.

What are moles?

The mole is a SI unit of measurement that is used to calculate the quantity of any substance.

The reaction is

S +  O₂   →   SO₂

The number of moles of SO₂ is 1.50 mol

1 mole of S produce 1 mole of SO₂

Then, 1.5 mole of S will produce 1.5 SO₂

Thus, the moles are 1.5.

Learn more about moles

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What temperature in Kelvin is 52 degree C?

Answers

Answer:

325 K

Explanation:

The condition of having a small amount of gravity is called _____.
free fall

ISS

microgravity

Answers

Answer:

The effects of microgravity can be seen when astronauts and objects float in space. Microgravity can be experienced in other ways, as well. "Micro-" means "very small," so microgravity refers to the condition where gravity seems to be very small.

ANSWER: MICROGRAVITY

Explain whether smoke filling up a room is diffusion or not.​

Answers

Answer:

It is diffusion

Explanation:

Diffusion occurs when particles move from relatively high concentration to relatively low

Answer:

it is diffusion

Explanation:

smoke rises from one corner of the room and spreads to the rest of the room, resulting in diffusion

What is the purpose or role of the urinary and excretory systems?*
A. digest food materials that come into the body
B. filter and remove liquid and solid waste
C. transport wastes throughout the body. D.regulate the body using hormones

Answers

Explanation:

B. filter and remove liquid and solid waste

7. Look at the graph in Figure 14.10 on page 420. What two observations did
Jacques Charles make about the behavior of gases from similar data?

Answers

The gases used to inflate, the airbag are able to absorb a considerate amount of energy when they are compressed . Hope I helped:)

Lights give off energy in the form of thermal energy and
energy

Answers

Answer: Energy, or the ability to do work, can exist in many different forms. ... The stage lights use electrical energy and give off both light energy and thermal energy, commonly called heat.

Explanation:

Hope this help

Why don't we feel the air pressing on us all the time?

Answers

Answer: Why don't we feel the air pressing on us all the time?

Explanation:

Because air is a fluid, the weight of the air is transmitted to the palm of your hand and to the back of your hand at the same time. These forces cancel so that your hand overall feels no net force

Answer:the gravity in the atmosphere is pulling all the air so we can survive

Explanation:

Mariyam, a marine biologist, measures the length of a great white shark at 4.5 m long and its teeth at an average of 50 mm long. She wants to convert both measurements to centimeters.

What should her new numbers be?

shark length: .45 cm; teeth: 0.50 cm
shark length: 45.0 cm; teeth: 50 cm
shark length: 450 cm; teeth: 5.0 cm
shark length: 4500 cm; teeth: 5.0 cm

I cant figure this out!!

Answers

Answer:

Its C. Please mark me brainliest if this helped

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