yall help, i missed like a week
some of them are wrong, I need all of 1 and 2​

Answer:

c

Explanation:

Wavelength = Speed of Light ÷ Frequency

                     = (2.99 × 10⁸ m/s) ÷ ( 2.45 × 10⁹ /s)

                     = 1.22 × 10⁻¹ m

The wavelength of a light of frequency   2.45 × 10⁹ /s is 1.22 × 10⁻¹ m.

Notes:

Hz ≡ /s

Answer:

D: Na

Explanation:

Hope this helps!

Have a nice day!!

:D

Write a Balanced Equation for the decomposition

CaCO₃     →     CaO    +    CO₂

Find Moles of CO₂ Produced

Since the mole ratio of  CaCO₃  to CO₂ is 1 to 1,

the moles of CaCO₃ = moles of CO₂

moles of CaCO₃   = mass ÷ molar mass

                             = 300 g ÷ 100.087 g/mol

                             = 2.997 moles

∴ moles of CO₂ = 2.997 moles

Determine Mass of CO₂

Mass = moles × molar mass

         = 2.997 mol × 44.01 g/mol

         = 131.9 g

Explanation:

there are 8 atoms of hydrogen

Answer:

B: Microscopic organisms are not made of cells

Explanation:

Answer:

A

Explanation:

it's a because model is like the same thing as walking on a Runway but it's like a model in the medical field

Answer:

3  1-butene, Z-2-butene, and E-2-butene.

Explanation:

Since 2-butene exists as two stereoisomers, three products are possible from the reaction of potassium ethoxide with 2-bromobutane. The products are, of course, 1-butene, Z-2-butene, and E-2-butene.

Answer:

3d

Explanation:

Answer:

Saponification

Explanation:

When treated with a base such as NaOH, the ester is transformed back to alcohol and the sodium salt of carboxylic acid. Saponification is the name given to the reaction since it is utilized in the production of soap.

Answer:

Their speed = 69.9043 miles per hour

Their speed = 112.5 kilometers per hour

Explanation:

Answer:

b).   0.732

Explanation:

52g Na₂SO₄ x     1 mol Na₂SO₄       x      2 mol Na

                          -------------------------      --------------------  =  0.732 mol Na

                           142.04 g Na₂SO₄       1 mol Na₂SO₄

Atomic Mass Units

Na₂ = 22.99 x 2 = 45.98

S     = 32.06

O₄ = 16 x 4 = 64

Na₂SO₄ = 45.98 + 32.06 + 64 = 142.04

There are 2 moles of Na in 1 mole of Na₂SO₄

Answer:

14

Explanation:

Answer:

Elements in the same group has different physical properties such as boiling and melting points. However there are trends of their physical properties down the group.

Explanation:

You should look at the perdoic table to for extra help

The boiling points and melting points of the given elements does not support the claim that elements of the same group have similar physical properties.

The boiling point of a substance is the temperature at which it changes from liquid state to gaseous state. Melting point is the temperature at which the substance changes from solid to liquid state.

Elements in the same group shows similar physical and chemical properties. But from the boiling and melting point we cant say that they are in the same group.

Elements in a group shows a trend in boiling point and melting point but cannot be distinguished with this from other groups.

Hence, boiling point and melting point of the elements do no support for the similar properties in a group.

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Your question is incomplete, but most probably your full question was,

Do the boiling points and melting points of these elements support the claim that elements of the same group have similar physical characteristics? (image uploaded)

Explanation:

The nomenclature of ionic compounds is given by:

1. Positive is written first.  And if the metal atom has various oxidation states then its oxidation state is to be mentioned in brackets with help of roman numbers

2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.

1.)  : Calcium chloride  (Correct)

In the given compound, calcium has oxidation state of +2 and chlorine has oxidation state of -1.The name is correct.

2.)  : Copper (II) oxide   (Incorrect)

In the given compound,copper has the oxidation state of +1 and oxygen has oxidation state of -2.So ,the correct name will be Copper (I) oxide.

3.)  : Lead (II) sulfide   (Incorrect)

In the given compound, lead has the oxidation state of +4 and sulfur has oxidation state of -2. So ,the correct name will be Lead (IV) sulfide.

To determine the most similar element identify the atomic number of the element and other properties such as state of the matter, color, conductivity, or boiling point.

In the period table, elements are arranged based on two main factors:

Now, if you know both the atomic number or the properties you can determine which element is the most similar to the element that you have.

Note: This question is incomplete because there is no information bout the element "oregano"; due to this, I answered it based on general knowledge.

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Answer:

First one answer is physical and other remaning chemical

Answer:

Hydrogen is a colorless, tasteless, and odorless gas.  

physical

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Hydrogen is very combustible in the presence of oxygen.  

chemical

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Hydrogen is very reactive with most elements.  

chemical

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Hydrogen is the least dense of all elements.  

physical

Answer:

They will form a hydrogen bond with the oxygen atom and the polar hydrogen atom.

Between a water molecule and an ethanol molecule, a hydrogen bond can occur between a lone pair of electrons on the Oxygen and  a Hydrogen in water and the Polar hydrogen of an ethanol molecule.

Hydrogen bonding is an interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons.

It is a bond is weaker than an ionic bond or covalent bond but stronger than van der Waals forces.

In the given question, They will form a hydrogen bond with the oxygen atom and the polar hydrogen atom.

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Answer:

Elements in which the d-sublevel is being filled have the properties of metals

Elements in which the d-sublevel is being filled have the properties of;

transition metals.

In quantum theory the sublevel is an energy level. Now, the d-sublevel in atomic configuration has 5 orbitals and as such can contain a maximum of 10 electrons.

Now, this d-sublevel is used primarily by elements called "transition elements" as they are also called d-block elements.

However, these transition elements are also called transition metals because all the transition elements possess properties of metals generally.

In conclusion, elements in which the d-sublevel is being filled have the properties of transition metals.

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Answer:

Octane

Explanation:

What is CH3CH2CH2CH2CH2CH2CH2CH3?

Octane - CH3CH2CH2CH2CH2CH2CH2CH3.

Answer:

brainless me plss i help you out

Answer:

The traditional electrolyte for aluminium electrolysis is based on molten cryolite (Na3AlF6), acting as solvent for the raw material, alumina (Al2O3).Metals are found in ores combined with other elements. Electrolysis can be used to extract a more reactive metal from the ore.

Aluminum can and is used as both anodes and cathodes in electrochemical cells, but there are some peculiarities to using it as an anode in aqueous solutions. As you note, aluminum forms a passivating oxide layer quite readily, even by exposure to atmosphere. In an aqueous solution, if the potential is high enough, OH− and O2− are generated at the anode, which can then react with the aluminum to produce aluminum oxide. Al^3+ can also be generated directly. The electric field will draw the anions through the growing aluminum oxide layer towards the aluminum surface and the Al^3+ towards the solution, making the oxide layer grow both away from the electrode surface and into the surface of the electrode. In this way, coatings thicker than the normal passivation in air can be produced. However, aluminum oxide is a good electrical insulator, thus if a dense non-porous layer is grown, it will become impossible to pass current through it and growth will stop, leaving a relatively thin oxide layer (this is how the dielectric layers in electrolytic capacitors are made). This is the normal behaviour in aqueous solutions at near-neutral pH (5–7).

However, if a thick aluminum oxide layer is desired (e.g. to produce coatings on aluminum parts for dying or durability), maintaining porosity is necessary to avoid completely blocking access to the surface. One technique that is commonly used is using a low pH solution, which tends to redissolve some of the oxide and neutralize some of the formed OH−, leaving pores in the oxide layer through which the ions can travel and continue to react. These pores also give a good structure to retain dyes or lubricants, but generally need to be sealed after to protect against corrosion.

Bromine needs to gain one more electron to have a noble gas configuration or 8 valence electrons, & potassium needs to lose one so they make a transference of electrons in an ionic bond.

Ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, or between two atoms with sharply different electronegativities, and is the primary interaction occurring in ionic compounds.

Ionic bonding results in compounds known as ionic, or electrovalent, compounds, which are best exemplified by the compounds formed between nonmetals and the alkali and alkaline-earth metals.

The charge of a cation or anion is denoted as a superscript after the formula of the ion. A + sign denotes a positive charge resulting from loss of electrons. A - sign denotes a negative charge resulting from gain of electrons.

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Answer:

Freezing and condensation

Explanation:

Because they are exothermic, they release energy

One:

plants make their own food through a process known as photosynthesis

Two:

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy and stored in the form of starch which can be used later

Three:

Photosynthesis converts carbon dioxide and water into oxygen and glucose. Glucose is used as food by the plant and oxygen is a by-product.

Answer:

1. b

2. a

3. b

Explanation:

Answer:  A) Rock formed by...magma or lava

Explanation:

As the question says, igneous rocks are formed from the cooling and solidification of magma or lava.

just a bit of visual aid thanks to Thoughtco.

Answer:

It is the first one - Rock formed by the cooling and solidification of hot liquid magma or lava.

Explanation: