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Aleksandr-060686 [28]
3 years ago
7

Rubidium has two naturally occurring isotopes: Rb-85 with mass 84.9118 amu and a natural abundance of 72.17 %, and Rb-87 with ma

ss 86.9092 amu and a natural abundance of 27.83 %. Calculate the atomic mass of rubidium.
Mathematics
1 answer:
lions [1.4K]3 years ago
8 0

Answer:

The atomic mass of rubidium is 85.468 u

Step-by-step explanation:

To determine the average atomic mass of an element, we take the weight average of the atomic masses of its naturally occurring isotopes. This means that alll isotopes together are calculated by multiplying the atomic mass  and the percentage of abundance . So we have sum of all the different isotopes ( which is 100 % of abundance)

For naturally occurring rubidium, there are 2 isotopes.

mass of Rb-85 x abundance + mass of Rb-87 x abundance

84.9118 x 0.7217 + 86.9092 x 0.2783 = 85,46767642

On the periodic table we can see for Rubidium 85.468 u which is the average atomic mass of Rubium ( and its 2 naturally occurring isotopes).

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Let $G$ denote the centroid of triangle $ABC$. If triangle $ABG$ is equilateral with side length 2, then determine the perimeter
belka [17]
Hey there!

You are trying to find the perimeter of triangle ABC. Each side is 2. Since there are 3 sides on a triangle, multiply 2 by 3 to get 6. You do not need the centroid for this problem.

I hope this helps!
5 0
3 years ago
2х - бу = 2<br>x + бу = 28​
scZoUnD [109]

Answer:

x = 10

y = 3

Step-by-step explanation:

Given

2x - 6y = 2

x + 6y = 28

Add both equations

2x + x -6y + 6y = 2 + 28

3x = 30

Divide both sides by 3

x = 30/3

x = 10

Substitute 10 for x in either equations to get y

Using equation 2 , we have

x + 6y = 28

10 + 6y = 28

Subtract 10 from both sides

10 - 10 + 6y = 28 - 10

6y = 18

Divide both sides by by 6

y = 18/6

y = 3

Therefore

x = 10

y = 3

7 0
3 years ago
Pls help Im very stuck on this and don’t understand
Lady bird [3.3K]

Answer:

C. 85 degrees

Step-by-step explanation:

Step 1: Set up equation

x + 57 + 96 + x = 131

Step 2: Solve for <em>x</em>

2x + 153 = 131

2x = -22

x = -11

Step 3: Find m∠RQU

m∠RQU = 96 + <em>x</em>

m∠RQU = 96 - 11

m∠RQU = 85°

8 0
3 years ago
Can anyone give me the answer? I’ll give brainleist
creativ13 [48]

Answer: 22 i think

Step-by-step explanation:

add all sides together

8 0
3 years ago
Read 2 more answers
Two angles form a linear pair. The measure of one angle is 1/3 of the other angle. Find the measure if each angle
sdas [7]

Answer:

<em>The measure of the angles is 45° and 135°</em>

Step-by-step explanation:

When two lines intersect, a linear pair of angles is formed. Two angles are said to be linear if they are adjacent, so a linear pair of angles must add up to 180 degrees.

Let's call x and y the two required angles. Knowing they form a linear pair:

x+y=180

We also know one angle is 1/3 of the other angle, thus:

x=y/3

Or, equivalently:

3x=y

Substituting y into the first equation:

x+3x=180

Simplifying:

4x=180

Solving:

x=180/4=45

The other angle is:

y=3x=3\cdot 45=135

Thus the measure of the angles is 45° and 135°

5 0
3 years ago
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