Question

There is an average of 3.5 x 10^−2 kilograms of dissolved salt in each liter of seawater. The Pacific Ocean contains approximately ​ 6.6 × 10^20 ​ liters of seawater. About how many kilograms of dissolved salt are in the Pacific Ocean? Enter your answer, in scientific notation, in the boxes. __×__10 kg

Answer 1

The answer is: 
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   " 2.3 * 10^(19) "  kg  {dissolved salt in the Pacific Ocean} .
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Explanation:
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3.5 * 10⁻² * 6.6 * 10⁽²⁰⁾  = ? kg dissolved salt in the Pacific Ocean.
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→ 3.5 * 10⁻² * 6.6 * 10⁽²⁰⁾  = 3.5 * 6.6 * 10⁻² * 10²⁰⁾ ;
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Note the following property of exponents:
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xᵃ * xᵇ = x⁽ᵃ⁺ᵇ⁾ ;  so;  10⁻² * 10²⁰ = 10⁽⁻² ⁺ ²⁰⁾ = 10⁽ ¹⁸ ⁾ ;

→ So; we can rewrite our expression as:
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  3.5 * 6.6 * 10⁽ ¹⁸ ⁾ ;

→ Note: 3.5 * 6.6 = 23.1 ---> Round to 2 (two) significant figures:  23 ;

Answer:  23 * 10⁽ ¹⁸ ⁾ ;  to write in scientific notation; write the "whole number" as: "2.3" (a single digit, whole number integer, followed by a decimal", and adjust the exponent following the "10" accordingly, to make the value equal; and we have:
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   " 2.3 * 10^(19) "  kg {dissolved salt in the Pacific Ocean} .
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Answer 2

This is the answer check it out