Name: Celocia, Joshua James S. Date: February 23, 2021
Program and Year: BSCE_1A_C1 Score:
Activity 1.1: The International System of Units
A. Complete the table in reference to the SI System Redefinition.
Base Unit Defining Constant Defining
Constant Symbol
Numerical Value
Kilogram Planck constant h6.62607015 ×10−34
Meter speed of light in vacuum c299,792,458
Second hyperfine transition frequency
of Cs
∆νCs 9,192,631,770
Kelvin Boltzmann constant k1.380 649 ×10−23
Mole Avogadro constant NA6.02214076 × 1023
Ampere elementary charge e1.602176634 × 10−19
Candela luminous efficacy Kcd 683
B. Answer the following questions.
1. Why do you think that a universal system of measurement is necessary in science?
Measurements are involved in nearly all real science. In science, a universal
measurement system is important, or at least very convenient, in order to make it
possible for different scientists to inform each other about their work on what they
have done and what the results are and also to work together on the same thing for
different scientists in different locations. In today's world, the universal system used is
the "SI" system, or the "metric" system. SI is designed to make it easy to do and
comprehend measurements and calculation, which is one of the main reasons
scientists have used it.
2. Why does the SI Measurement System use “kilogram” instead of “gram” as the
base unit of mass?
The kilogram is the base unit of mass since a standard range of functional
electrical units was selected by electrical engineers in the late 19th century. They
were a hit with their functional units, and we are still using them today: ohm, volt, and
ampere. Practical electrical units, ampere, volts, and ohms, on the other hand, were
not compatible with cm, g, s, or m, g, s. By coincidence, however, they were
compatible with m, kg, s. That is why the kilogram was selected in 1960 as the base
unit of mass in the SI system.