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3 years ago

List four elements used in dfds, draw the symbols, and explain how they are used.

1 answer:

3 0

a. Processes: - Is a series of steps that manipulate data b. Data flows: - Describes the data and the information elements passing between external entities, processes and data stores c. Data stores: - A place to keep data for later use d. External entities:- The original source of data or the receiver of information

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Is it possible to decrease resistance of the wire without changing the material it's made out of?

loris [4]

Yes, it is possible to decrease the resistance of a wire without changing the material it made out of. This is because, there are many factors which affect the resistance of a wire. These factors can be manipulated to change the resistance of the wire. The factors include: cross sectional area of the wire, length of the wire, temperature and the material of the wire. The other three factors can be manipulated to change the resistance of the wire without changing the material of the wire.

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3 years ago

Give the product of the reaction of excess benzene (2 equivalents) with dichloromethane and alcl3.

SOVA2 [1]

Hello!

The product of the reaction of excess benzene with dichloromethane is diphenylmethane.

The reaction that benzene undergoes with dichloromethane is a Friedel-Crafts Alkylation, in which firstly Benzene is alkylated to Benzyl Chloride, and after that, the Benzyl Chloride reacts with another equivalent of Benzene to form the compound Diphenylmethane. The Reaction Scheme is shown in the image below:

Have a nice day!

5 0

3 years ago

What is the empirical formula of a compound that is 18.8% Li, 16.3% C , and 64.9% O

zlopas [31]

Greetings!

To find the empirical formula you need the relative atomic mass of each element!

Li = 6.9

C = 12

O = 16

You can simply change the percentages into full grams

Li = 18.8g

C = 16.3g

O = 64.9

Then you use this to find the Number of moles = amount in grams / atomic mass

Li = 18.8 ÷ 6.9 = 2.7246

C = 16.3 ÷ 12 = 1.3583

O = 64.9 ÷ 16 = 4.0562

Then divide each number of moles by the smallest value:

Li = 2.7246 ÷ 1.3583 = 2.0

C = 1.3583 ÷ 1.3583 = 1

O = 4.0562 ÷ 1.3583 = 2.9 ≈ 3

So that means that there are 2 Li, 1 C, and 3 O

Empirical formula would be:

Li₂CO₃

Hope this helps!

3 0

3 years ago

As more bulbs are connected in series in a circuit, what happens to the brightness with which each glows?

madam [21]

They dim unless more volts are added (batteries")

8 0

2 years ago

Read 2 more answers

A bond in which one atom contributes both bonding electrons to a covalentbond

yKpoI14uk [10]

<h3>Answer:</h3>

A coordinate bond

<h3>Explanation:</h3>

A chemical bond is a force of attraction between two or more atoms of elements.
Covalent bond is a type of chemical bond that occurs between non-metal atoms.
It occurs as a result of sharing of electrons between the non-metal atoms.
Atoms involved in covalent bond formation may contribute equally to the bond formation or the electrons shared may come form one of the atoms.
When the electrons shared in a covalent bond are derived from one atom, then the covalent bond is known as a coordinate bond.

4 0

3 years ago