What is Force?
Force is a term in physics used to describe a push or pull on an object. A force can make an object go faster, slow down, remain in shape, or change shape. For example, when you push a shopping cart at the grocery store, you are putting force on the cart which is causing it to get faster and move with you as you are walking!
How is Force Measured?
Force is measured in Newtons, abbreviated “N” for short. A newton is the amount of force needed to accelerate (move) one gram of mass by one centimeter per second squared. Force can also be measured in dynes and pound forces.
What is Acceleration?
Acceleration is the amount of change of an object’s velocity (speed). For example, when you step on the gas pedal in your car, your car speeds up, and when you step on the brake, your car slows down. When your car speeds up and slows down, it is accelerating!
How is Acceleration Measured?
The standard unit of measure for acceleration is m/s^2, where the speed is in meters per second and time is in seconds. Since acceleration has both a magnitude (size) and a direction, we call it a vector quantity.
How are Force and Acceleration Related?
Force and acceleration can be related to each other through this equation:
F = m * a
F = amount of force applied to object
m = mass of object
a = acceleration of object
When you look at the periodic table, it may look scattered, almost unorganized. You may wonder, why isn’t it simply a rectangle, and what are all those letters and numbers on it?
The shape of the periodic table is determined by the elements’ atomic number, valence electrons, and the number of energy levels they contain. Reading from left to right, we will notice that the number at the very top of the box, called the atomic number, increases with each following element. The atomic number is also what defines an element because the atomic number is equal to the number of protons in that element. In any element, the number of protons, positive particles in the nucleus of elements, is what makes it that specific element. Therefore, if we have an element with three protons, we know it is lithium because the number of protons equals the atomic number of the element.
The valence electrons and chemical properties of an element determine its column on the periodic table. Valence electrons are the electrons on the outermost energy level of an atom. All atoms have energy levels, starting from the innermost that holds two electrons, the next level with eight, and each following level having a specified capacity for electrons. Therefore, on the leftmost column of the periodic table, all those elements have only one valence electron, meaning their outermost energy level only has one electron. However, in the rightmost column, all the elements have the maximum valence electrons for the element. However, this gets more complex when we go lower in the periodic table, so another way to recognize groups, or columns, is by their similar chemical properties. Since the elements in the same column have the same number of valence electrons, they have similar reactivity among other chemical characteristics.
The number of energy levels of an element determines which row, or period, it belongs to. In the first period, we have hydrogen and helium, both of which only have one energy level, therefore placing them in the very first row. However, in the next period, all the elements require two energy levels to hold all their electrons. From this , we know that if we were to take the element magnesium (atomic number 12), that it would have three energy levels since it’s in the third period!
Now let’s do a little trivia! Find calcium (Ca).