All categories

3 years ago

Simplify the numercial expression 13-2x5

Chemistry

2 answers:

nadya68 [22]3 years ago

7 0

Answer:

you multiply 2x5=10 then,

subtract 13-10=3

i have a easier way to do it its called PEMDAS because first you do

Parentheses

Exponents

Multiply

or Devided (which ever comes first)

Addition

or Subtract (which ever comes first)

Tema [17]3 years ago

4 0

Answer:

Explanation:

2x5 is 10 then 13-10 is 3

You might be interested in

Cathode rays were shown to be a stream of _____. protons electrons neutrons quarks

Murljashka [212]

It's B) electrons, is the right answer

7 0

3 years ago

In many environments, the temperature of the ground and the air right above the ground are both very similar in the middle of th

loris [4]

Answer:

yes i think so

Explanation:

4 0

2 years ago

What are the rules for writing

Assoli18 [71]

The rules of writing name is that they start with a big letter LIKE this and ends like this

4 0

2 years ago

A neutral atom has equal numbers of and electrons.

Illusion [34]

True

true

true

true

true

true

6 0

2 years ago

Enter your answer in the provided box. The atomic masses of 63Cu (69.17 percent) and 65Cu (30.83 percent) are 62.94 and 64.93 am

dybincka [34]

Answer: The average atomic mass of copper is 63.55 amu.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

For $_{29}^{63}\textrm{Cu}$ isotope:

Mass of $_{29}^{63}\textrm{Cu}$ isotope = 62.94 amu

Percentage abundance of $_{29}^{63}\textrm{Cu}$ = 69.17 %

Fractional abundance of $_{29}^{63}\textrm{Cu}$ isotope = 0.6917

For $_{29}^{65}\textrm{Cu}$ isotope:

Mass of $_{29}^{65}\textrm{Cu}$ isotope = 64.93 amu

Percentage abundance of $_{29}^{65}\textrm{Cu}$ = 30.83 %

Fractional abundance of $_{29}^{65}\textrm{Cu}$ isotope = 0.3083

Putting values in equation 1, we get:

$\text{Average atomic mass of Copper}=[(62.94\times 0.6917)+(64.93\times 0.3083)]\\\\\text{Average atomic mass of copper}=63.55amu$

Hence, the average atomic mass of copper is 63.55 amu.

4 0

2 years ago