someone please help me i dont understand how too do these​

Answer:

Periodic trends are specific patterns that are present in the periodic table that illustrate different aspects of a certain element, including its size and its electronic properties. Major periodic trends include: electronegativity, ionization energy, electron affinity, atomic radius, melting point, and metallic character. Periodic trends, arising from the arrangement of the periodic table, provide chemists with an invaluable tool to quickly predict an element's properties. These trends exist because of the similar atomic structure of the elements within their respective group families or periods, and because of the periodic nature of the elements.

Explanation:

Electron Affinity:

electron affinity is the ability of an atom to accept an electron. Unlike electronegativity, electron affinity is a quantitative measurement of the energy change that occurs when an electron is added to a neutral gas atom. The more negative the electron affinity value, the higher an atom's affinity for electrons.

Electron affinity generally decreases down a group of elements because each atom is larger than the atom above it (this is the atomic radius trend, discussed below). This means that an added electron is further away from the atom's nucleus compared with its position in the smaller atom. With a larger distance between the negatively-charged electron and the positively-charged nucleus, the force of attraction is relatively weaker. Therefore, electron affinity decreases. Moving from left to right across a period, atoms become smaller as the forces of attraction become stronger. This causes the electron to move closer to the nucleus, thus increasing the electron affinity from left to right across a period.

Electron affinity increases from left to right within a period. This is caused by the decrease in atomic radius.

Electron affinity decreases from top to bottom within a group. This is caused by the increase in atomic radius.

Take the given weight (784.616g) and divide it by the atomic weight of H2SO4.

The atomic mass can be found under the element symbol on the periodic table. You must add the atomic mass for each element in H2SO4 to get the total. The total atomic mass for H2SO4 will be about 98g.

Then divide the weight by this number.

784.616g/98g = 8.006 moles

Therefore, there is approximately 8 moles.

Answer:

[tex]\huge\boxed{\sf 21.6\ moles\ of\ MgO}[/tex]

Explanation:

Here,

for 1 mol of O₂, 2 moles of MgO are produced.

Also,

At STP:

1 mol of O₂ = 22.4 dm³/mol molar value

Moles in 242 L of O₂:

= volume / molar value

= 242 / 22.4

= 10.8 mol

Since:

1 mol of O₂ = 2 moles of MgO

10.8 mol of O₂ = 2 × 10.8 moles of Mgo

10.8 moles of O₂ = 21.6 moles of MgO

[tex]\rule[225]{225}{2}[/tex]

Answer:

an element is a substance that cannot be broken down into any other substance. each element is made up of its own type of atom, which is why each element is different and unique than the other.

Answer:

In chemistry, an element is a pure substance which cannot be broken down by chemical means, consisting of atoms which have identical numbers of protons in their atomic nuclei. The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number

hope this helps! :) :) :)

Answer:

Average ocean pH is now 8.1 and varies seasonally

Explanation:

Answer:

chlorine-35 (75.53 percent) and chlorine-37 (24.47 percent)

Answer: Your answer is carbon dioxide in the air

Hope this helps!

Answer:

I think it's true

Explanation:

jnwnwnaokajz

Answer: Auxanometer

Explanation:

An auxanometer (Gr. auxain= "to grow" + metron= "measure") is an apparatus for measuring the increase of growth in plants. Sensitive auxanometers allow measurement of growth as small as a micrometer, which allows measurement of growth in response to short-term changes in atmospheric composition.

I hope this helps!

Answer:

An auxonometer is used to measure production in plants

Answer:red super giant

Explanation:

just look off the sides

Answer:

igneous rocks have distinct layers that represents the time period

Explanation:

They are not formed overtime, nor have layers. They are just hardened lava.

Answer:

CO2

Explanation:

As CO2 soaks up this infrared energy, it vibrates and re-emits the infrared energy back in all directions.

Answer:

1)Br

2)Ar[4s,3d,4p1]

3) 7e

4) kr

Answer:

530 g

Explanation:

1 mole of Sodium Carbonate = 106g

5 moles = 106*5 = 530g

Answer:

B.

F.

Explanation:

Answer: Yes

Helium (He) and Neon (Ne) are both noble gases. They are very common in our lives. Helium has a atomic number of 2, and neon has one of 10.

Hope this helps you!

Answer:

In this assignment, you will write and balance a chemical equation. Then,you will use a table of enthalpy values to calculate the energy change in the reaction. Next, you will create a model of the energy change in the reaction.Finally, you will write an explanation that describes the energy change in the reaction.

Explanation:

Answer:

4

Explanation:

nonmetals are brittle and dull.

Answer:

degree to which a substance dissolves in a solvent to make a solution

is this ok

Answer:

Have Fun

Explanation:

Answer:

The same number of atoms of each element must appear on both sides of a chemical equation. However, simply writing down the chemical formulas of reactants and products does not always result in equal numbers of atoms. You have to balance the equation to make the number of atoms equal on each side of an equation.

Explanation:

Answer:

7 to 5

Explanation:

power of 500 to 5

Answer:

Red light.

Explanation:

On one end of the spectrum is red light, with the longest wavelength. Blue or violet light has the shortest wavelength. White light is a combination of all colors in the color spectrum. It has all the colors of the rainbow.

Answer:

red

Explanation:

red has a wavelength of 630-700 nm

Answer:

The way its parts are arranged ....I think

Answer:

The purpose of the experiment is to see how water of different temperature and salinity affect the density.

Explanation:

Temperature and salinity directly affect the density of the water. Water of low temperature is more dense than water of high temperature, BUT, (fresh)water with no salt is less dense than (sea)water with more salt, so temperature and salinity change density of water.

Answer:

Please post the answers for the other questions on my page!! I will give you brainiest!! Please :(

Explanation:

Answer:

The mixture of ethanol and water is a liquid-liquid solution. The solvent is Water.

Explanation:

Answer:

The second statement

Explanation:

Because it can't be broken by physical means

A compound is a pure substance because  its molecule cannot be broken down into simpler particles by physical means. Therefore, option B is correct.

A kind of matter with a predictable chemical composition and physical properties is referred to as a chemical substance. According to certain references, chemical substances cannot be physically divided into their component parts.

A pure material has a predictable chemical make-up. A material is the same everywhere it is sampled. The safest pure examples for chemistry homework are elements and compounds. Gold, silver, helium, sodium chloride, and pure water are a few examples.

Water only includes one kind of molecule, making it a pure substance. Only molecules made up of one oxygen atom joined covalently to two hydrogen atoms can be found in pure water.

Thus, option B is correct.

To learn more about pure substance, follow the link;

https://brainly.com/question/24462192

#SPJ2