Answer: All apply
The periodic table is an arrangement of the chemical elements in the form of a table, ordered by:
-Their atomic number (number of protons)
-Their configuration of electrons
-Their chemical properties
It was progressively developed over time as the scientific knowledge advanced; for this reason many modifications and corrections might be done in the future.
Its usefulness lies in the fact that it allows the existing elements to be organized in a more structured and coherent way, according to the chemical properties they possess. Dividing the table into rows and columns, which represent the periods and groups or families.
Then, with the location and classification of an element according to its group, we can determine how it acts by knowing its chemical and physical characteristics.
This is how with this configuration can be distinguished 4 sets of chemical elements, according to the ease of their atoms to lose or gain electrons, transforming into ions: metals, semimetals, non-metals and noble gases.
This has helped to predict the existence of various elements that have not yet been discovered, because by elements already located in the table and the periodicity found, <u>there are still empty spaces that indicate the composition of the element that has not yet been found</u>.
In addition, this table helps to simplify in some way the teaching of chemical elements and facilitates their learning, as well as their usage in the development of technological innovations.
Answer:
For vector u, x component = 10.558 and y component =12.808
unit vector = 0.636 i+ 0.7716 j
For vector v, x component = 23.6316 and y component = -6.464
unit vector = 0.9645 i-0.2638 j
Explanation:
Let the vector u has magnitude 16.6
u makes an angle of 50.5° from x axis
So 
Vertical component 
So vector u will be u = 10.558 i+12.808 j
Unit vector 
Now in second case let vector v has a magnitude of 24.5
Making an angle with -15.3° from x axis
So horizontal component 
Vertical component 
So vector v will be 23.6316 i - 6.464 j
Unit vector of v 
To solve this problem we will apply the linear motion kinematic equations. From the definition of the final velocity, as the sum between the initial velocity and the product between the acceleration (gravity) by time, we will find the final velocity. From the second law of kinematics, we will find the vertical position traveled.

Here,
v = Final velocity
= Initial velocity
g = Acceleration due to gravity
t = Time
At t = 4s, v = -30m/s (Downward)
Therefore the initial velocity will be


Now the position can be calculated as,

When it has the ground, y=0 and the time is t=4s,


Therefore the cliff was initially to 41.6m from the ground
Answer:
The variation and distribution of traits in a population depend on genetic and environmental factors. Genetic variation can result from mutations caused by environmental factors or errors in DNA replication, or from chromosomes swapping sections during meiosis.
Explanation:
Hope this helps!