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The prefix used for 10-18 is:
The prefix used for 10-18 is atto-
Additional Information: A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or submultiple of the unit. Each prefix has a unique symbol that is prepended to any unit symbol. Some important prefixes are given below:
One atomic mass unit (amu) is closest to:
The number of base SI units is:
The standard units of measurement defined by the ISU for the seven base quantities are SI base units All other SI units are derived from it.
Additional Information: 7 Basic SI units with their quantities are:
The SI unit of time is:
The S.I. unit of time is second(s).
Additional Information: A second can be defined as 1/86400th part of a mean solar day, i.e., =1/86400 × one mean solar day.
The two effective drugs which act as life-saving drugs for cancer therapy and AIDS victims respectively are:
Additional Information: Its mode of action has been linked to its ability to crosslink with the purine bases on the DNA; interfering with DNA repair mechanisms, causing DNA damage, and subsequently inducing apoptosis in cancer cells.
Which of the following statements is/are correct?
Since both statements A and B are correct, the correct option is D.
The coefficient in 6.65 × 104 is:
Here, 6.65 is the coefficient and 104 is the exponent.
Explanation: A coefficient is a number or an alphabet that is multiplied by a variable of a single term or the terms of a polynomial. For example, in the term 7x, 7 is the coefficient.
The ‘Candela’ is the unit of:
The number of significant figures in 3256 is:
The SI unit of electric current is:
So the Ampere is the SI unit of the current.
A number of significant figures in 0.001520 is:
If the true value for a result is 2.00 g and a student takes 2 measurements and reports the results as 1.95 g and 1.93 g, then we can conclude that:
The unit of amount of substance is:
Out of the numbers: 6.26, 5.8, 0.00267, 0.03, the one with the least significant figures is:
Therefore, the correct answer is 0.03
If the true value for a result is 3.00 m and a student records two readings as 3.01 m and 2.99 m, then we can conclude that:
Since the readings closely match the result and the expected value, the correct answer is that the values are both accurate and precise.
The number of significant figures in 3.1205 are:
The answer is 5 because all non zero digits and zero between the non zero digits are significant.
The scientific notation for 0.00016 is:
Move the decimal point to the right of 0.00016 up to 4 places.
The decimal point was moved 7 places to the right to form the number 1.6
Since the numbers are less than 10 and the decimal is moved to the right, so we use a negative exponent here.
⇒ 0.00016 = 1.6 × 10-4
Suppose the elements X and Y combine to form two compounds XY2 and X3Y2. When 0.1 mole of XY2 weighs 10 g and 0.05 mole of X3Y2 weighs 9 g, the atomic weights of X and Y are:
Let atomic weight of element X is x and that of element Y is y.
If we add the numbers 6.68 and 0.8, the result will be:
The correct option is B
In addition, the result cannot have more digits to the right of the decimal point than either of the original numbers.
Since there is only 1 digit after the decimal point in 0.8 so the result 7.48 should be rounded off to 1 decimal point i.e. 7.5.
Molecular mass of glucose molecule (C6H12O6) is:
Molecular mass: The sum of the atomic masses of all the atoms in a molecule of a substance is called the molecular mass of the molecule.
Generally, we use relative atomic masses of atoms for calculating the molecular mass of 1 mole of any molecular or ionic substances.
The molecular formula of glucose is C6H12O6
Molecular mass of C6H12O6 = 12 (Atomic mass of Hydrogen) + 6(Atomic mass of carbon) + 6(Atomic mass of oxygen)
= 12 × 1 + 6 × 12 + 6 × 16
= 12 + 72 + 96 = 180 u.