Chemistry, 19.09.2019 20:30 ajbrock1004

1) 1.24 x 10^3 + 1.564 x 10^1
2) 5.8 x 10^3 - 3.156 x 10^2
3) 1.24 x 10^8 / 2.87 x 10^4
4) 8.513 x 10^6 x 5.45 x 10^7
5) 1.24 x 10^3 x 33000
6) 4 x 10^3 + 7.65 x 10^4
7) 1000 + 3.156 x 10^5
8) 5.42 x 10^2 + 3 x 10^5

Answers: 1

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Answers

Answer from: Fdl52417

Answer :

The answer will be $\Rightarrow 1.24\times 10^4$

The answer will be $\Rightarrow 5.5\times 10^3$

The answer will be $\Rightarrow 4.32\times 10^3$

The answer will be $\Rightarrow 4.64\times 10^{14}$

The answer will be $\Rightarrow 4.1\times 10^{7}$

The answer will be $\Rightarrow 8.05\times 10^4$

The answer will be $\Rightarrow 3.166\times 10^5$

The answer will be $\Rightarrow 3.00\times 10^5$

Explanation :

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

The rule apply for the multiplication and division is :

The least number of significant figures in any number of the problem determines the number of significant figures in the answer.

The rule apply for the addition and subtraction is :

The least precise number present after the decimal point determines the number of significant figures in the answer.

(1) $(1.24\times 10^3)+(1.564\times 10^1)$

$\Rightarrow 1.2415\times 10^4$

In the given expression, 1.24 has 3 significant figures and 1.564 has 4 significant figures. From this we conclude that least precise number present after the decimal point is 2.

Thus, the answer will be $\Rightarrow 1.24\times 10^4$

(2) $(5.8\times 10^3)-(3.156\times 10^2)$

$\Rightarrow 5.484\times 10^3$

In the given expression, 5.8 has 2 significant figures and 3.156 has 4 significant figures. From this we conclude that least precise number present after the decimal point is 1.

Thus, the answer will be $\Rightarrow 5.5\times 10^3$

(3) $\frac{(1.24\times 10^8)}{(2.87\times 10^4)}$

$\Rightarrow 4.3205\times 10^3$

In the given expression, 1.24 has 3 significant figures and 2.87 has 3 significant figures. From this we conclude that 3 is the least significant figures in this problem. So, the answer should be in 3 significant figures.

Thus, the answer will be $\Rightarrow 4.32\times 10^3$

(4) $(8.513\times 10^6)\times (5.45\times 10^7)$

$\Rightarrow 4.6395\times 10^{14}$

In the given expression, 8.513 has 4 significant figures and 5.45 has 3 significant figures. From this we conclude that 3 is the least significant figures in this problem. So, the answer should be in 3 significant figures.

Thus, the answer will be $\Rightarrow 4.64\times 10^{14}$

(5) $(1.24\times 10^3)\times (33000)$

$\Rightarrow 4.0920\times 10^{7}$

In the given expression, 1.24 has 3 significant figures and 33000 has 2 significant figures. From this we conclude that 2 is the least significant figures in this problem. So, the answer should be in 2 significant figures.

Thus, the answer will be $\Rightarrow 4.1\times 10^{7}$

(6) $(4\times 10^3)+(7.65\times 10^4)$

$\Rightarrow 8.0500\times 10^4$

In the given expression, 4 has 1 significant figures and 7.65 has 3 significant figures. From this we conclude that least precise number present after the decimal point is 2.

Thus, the answer will be $\Rightarrow 8.05\times 10^4$

(7) $1000+(3.156\times 10^5)$

$\Rightarrow 3.16600\times 10^5$

In the given expression, 1000 has 1 significant figures and 3.156 has 4 significant figures. From this we conclude that least precise number present after the decimal point is 3.

Thus, the answer will be $\Rightarrow 3.166\times 10^5$

(8) $(5.42\times 10^2)+(3\times 10^5)$

$\Rightarrow 3.00542\times 10^5$

In the given expression, 5.42 has 3 significant figures and 3 has 1 significant figures. From this we conclude that least precise number present after the decimal point is 2.

Thus, the answer will be $\Rightarrow 3.00\times 10^5$

Answer from: Quest

$\frac{239}{94}pu+\frac{1}{0}n ====> \frac{y}{z}x+\frac{134}{54}xe+3\frac{1}{0}$

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137 subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54 subtract 54 from both sides.

40 = z

answer

$\frac{103}{40}x=\frac{103}{40}zr$

Answer from: Quest

No is the answer to the question

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1) 1.24 x 10^3 + 1.564 x 10^1
2) 5.8 x 10^3 - 3.156 x 10^2
3) 1.24 x 10^8 / 2.87 x 10^4<...

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