8. Carbohydrates on cell membranes help cells

How many core electrons are in a ground state atom of selenium?

Harman [31]

Electrons in an atom can be classified as core electrons and valence electrons. Valence electrons are those electrons which are present in valence shell and participates in bond formation. While, Core electrons are all remaining electrons which are not present in valence shell, hence not take part in bonding.

Atomic number of Selenium (Se) is 34 hence it has 34 electrons with following electronic configuration;

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁴

From electronic configuration it is found that the valence shell is 4, and the number of electrons present in valence shell are 6. So,

Core Electrons = Total Electrons - Valence Electrons

Core Electrons = 34 - 6

Core Electrons = 28

Result:
There are 28 core electrons in Selenium.

3 0

3 years ago

Draw the product formed when cyclohexene is reacted with H2 in the presence of Pt. Note: If adding hydrogen atoms to a carbon at

tigry1 [53]

Answer:

It has been drawn and uploaded as an attachment. Please download it to see the structure.

Explanation:

The product formed as a result of the reaction of cyclohexene with H2 in presence of Pt (platinum) can be described as catalytic hydrogenation. Catalytic hydrogenation is defined as the process of hydrogen addition in the presence of a catalyst, which in this case is platinum.

Note that Cyclohexene (alkene) is a hydrocarbon molecule represented by the chemical formula, C6H10 .

It consists of a double bond. During the hydrogenation reaction, the alkene undergoes an addition reaction to give alkane which is a saturated hydrocarbon as the product.

The first step in order to derive the product is to draw the chemical structure of cyclohexene and identify the double bond present in it.

The final product can be derived by replacing the double bond with the single bond and satisfying all the valences of the carbon atom. The final product structure has been drawn and uploaded as an attachment. Please download it to see the structure.

Ans:

The structure of the cyclohexane thus, formed has been shown as follows with all the hydrogen atoms:

3 0

3 years ago

Object A at 40ºC and object B at 80ºC are placed in contact with each other. Which statement describes the heat flow between the

Arada [10]

By the second law of thermodynamics:
Heat can not spontaneously flow from cold regions to hot regions without external work being performed on a system.
Heat transfer is the passage of thermal energy from a hot ( t B = 80° C ) to a colder body ( t A = 40° C ).
Answer: B ) Heat flows from object B to object A.

6 0

3 years ago

Read 2 more answers

Which part of an of the helium atom is positively charged

olchik [2.2K]

Nucleus because it is made of protons (which means positively charged)

6 0

3 years ago

DNA Mutations

vitfil [10]

Answer:

Explanation: