Periodic Table and Forces

• The periodic table organizes elements based on their atomic number and chemical properties.
• Elements in the same group (vertical column) have similar chemical properties due to having the same number of valence electrons.
• Elements in the same period (horizontal row) have the same number of electron shells

Forces

• A force is a push or pull that can cause an object to accelerate, decelerate, change direction, or change shape.
• Forces are vector quantities, meaning they have both magnitude and direction.
• The unit of force is the Newton (N).

Measuring forces

• Forces can be measured using various instruments, such as:
• Spring balances (also known as Newton meters) which measure force by the extension of a spring.
• Force sensors which use electronic transducers to convert force into an electrical signal.
• When using a spring balance, ensure it is zeroed before taking measurements.
• Read the scale carefully and ensure the force is applied along the axis of the spring balance.

Balanced and unbalanced forces

• Balanced forces occur when two or more forces acting on an object cancel each other out.
• When forces are balanced, the net force is zero, and the object remains at rest or continues moving at a constant velocity in a straight line (Newton's First Law).
• Unbalanced forces occur when the net force acting on an object is not zero.
• An unbalanced force causes the object to accelerate in the direction of the net force (Newton's Second Law).
• The acceleration is proportional to the net force and inversely proportional to the object's mass (F = ma).

Resultant forces

• The resultant force (or net force) is the single force that represents the vector sum of all forces acting on an object.
• To find the resultant force of forces acting in the same direction, add their magnitudes.
• To find the resultant force of forces acting in opposite directions, subtract their magnitudes. The direction of the resultant force is the same as the direction of the larger force.
• For forces acting at angles to each other, vector addition techniques (e.g., using scaled diagrams or resolving forces into components) are used to determine the resultant force.

Mass and weight

• Mass is a measure of the amount of matter in an object and is measured in kilograms (kg).
• Mass is a scalar quantity.
• Weight is the force of gravity acting on an object and is measured in Newtons (N).
• Weight is a vector quantity.
• Weight is calculated using the equation: Weight = mass × gravitational field strength (W = mg).
• The gravitational field strength (g) on Earth is approximately 9.8 N/kg.
• An object's mass remains constant regardless of its location, but its weight changes depending on the gravitational field strength.

Space

• Space is the boundless three-dimensional extent in which objects and events have relative position and direction.
• Near-vacuum: Space is not completely empty, but contains a very low density of particles.
• Contains electromagnetic radiation, magnetic fields and gravity.
• Celestial bodies:
• Planets: Large objects orbiting a star
• Stars: Massive, luminous spheres of plasma held together by their own gravity.
• Moons: Natural satellites orbiting planets.
• Asteroids: Rocky or metallic objects orbiting a star, smaller than planets.
• Comets: Icy bodies that release gas and dust as they approach a star.
• Galaxies: Enormous systems of stars, gas, dust, and dark matter held together by gravity.
• Universe: All of space and time and their contents, including galaxies, stars, planets, and all other forms of matter and energy.

Explore the periodic table's organization and element properties. Understand forces as pushes or pulls, their measurement using spring balances and sensors, and their vector nature.