Examples (portugal)

Examples of the application of Maths to other subjects (Portugal)

SUBJECT/TOPIC MATHS TOPIC Example

Chemistry Chemical elements Relative atomic mass

1st degree Equations weighted Average percentage

Most elements that exist in nature have isotopes. The element X consists of two isotopes.Consider the data provided in the following table:

Isotopes isotopic mass relative abundance

X(2 x−1)(4 x−1) 6,02 8%

X(3x−3)(3x) 7,02 92%

1. Please, indicate the number of neutrons of the less abundant isotope.3 x−3=2x−1⇔x=2Replacing x in 4 x−1by 2, we obtain4×2−1=7Replacing x in 2 x−1by 2, we obtain2×2−1=3As mass number = number of protons + number of neutrons7=3+number of neutrons⇔number of neutrons=7−3=4Answer: The number of neutrons of the less abundant isotope is 4.2. Write the nuclide of the most abundant isotope.3×2=63×2−3=3

X36

3. What is the serial number of the element X in the periodic table?The number of the element x in the periodic table, is 3 because the order number is equal to the atomic number.4. Calculate the relative atomic mass of the element X.6,02×0,08=0,48167,02×0,92=6,45846,4584+0,4816=6,94or

relative atomic mass =isotopicmassof the1 st×8+isotopicmassof the 2nd ×92

100=

6,02×8+7,02×92100

=48,16+645,84100

=6,94

Answer: The relative atomic mass of the element X is 6,94

Examples of the application of Maths to other subjects (Portugal)

PhysicsDisplacement and space traversed

Distance between two points

Pythagoras Theorem

The movement of a particle is described in the graphic .

calculate the displacement and the space traversed between:

1. .

2. .