The correct answer to the question is [tex]D)\ 6.9\times 10^{-4}[/tex]
EXPLANATION:
The magnitude of measurement of any physical quantity in scientific notation is expressed as follows-
Magnitude = [tex]p\times 10^n\ unit[/tex].
Considering the numerical part only, magnitude m = [tex]p\times 10^n[/tex].
Here, p ∈ Q, and 1 ≤ p ≤ 9.
Here, n is called the power or index of ten.
As per the question, we have m = 0.00069.
In proper scientific notation, the value is written as -
m = 0.00069
= [tex]6.9\times 10^{-4}[/tex] [ans]
Hence, 0.00069 can be written as [tex]6.9\times 10^{-4}[/tex] in scientific notation.
In scientific notation, 0.00069 is written as 6.9 × 10⁻⁴
Where N is a number between 1 and 10, and "a" is an integer, positive or negative number.
For instance;
Very small numbers.
Example; 0.0000000234
The decimal place will be moved towards the right 8 places. In this case the exponent will be negative.
Thus; the scientific notation is; 2.34 × 10⁻⁸
Very large numbers
example; 7689400
The decimal place will be moved to the left 7 places. In this case the exponent will be positive.
Therefore; the scientific notation will be; 7.6894 × 10⁷
In our question.
The number is 0.00069
Therefore, the decimal point will be moved to the right 4 places, therefore the exponent will be negative.
Therefore; the scientific notation will be; 6.9 × 10⁻⁴
Keywords; Scientific notation
Learn more about:
Level: Middle school
Subject: Mathematics
Topic: Standard form/scientific notation
Sub-topic: Writing numbers in scientific notation
