Explanation:
Elements that belong to same group contains same number of valence electrons. Hence, they tend to show similar chemical properties.
When we move across a period then number of electrons get added to the same shell. As a result, there will be no increase in size of elements.
Also, metals are the elements that belong to group 1, 2 and d-block elements are also known as metals. Metallic character of elements decreases when we move left to right in a periodic table.
As most reactive metals are placed on the left side of periodic table.
Since, size of elements increases on moving down the group. So, an element is able to easily lose its valence electrons because of less force of attraction between its nucleus and valence electrons.
As a result, there will be increase in reactivity of metals on moving down the group.
Thus, we can conclude that given sentences are as follows.
- Elements in the same group have the same number of valence electrons.
-
Elements in the same period have the same number of electron shells.
-
Metallic elements become less reactive as you move left to right in a period.
-
Metallic elements become more reactive as you move top to bottom in a group.
Nobody on here is going to write a entire cer for you
Explanation:
so then we would know about the reproduction system and how we are born and what happens with the cells inside the womens womb and how the sperm cell meets the egg cell and creates the egg
Answer
i’m in 7th grade but for this years science fair i did, “ how does temperature affect the elasticity of rubber bands”
Guide a growing plant through a maze.
8th Grade Science Plant Maze KiwiCo
Prove that plants really do seek out the light by setting up a simple or complex maze. This is a simple 8th grade science project with really cool results.
Blow out a candle with a balloon.
Blowing up a balloon with baking soda and vinegar is the classic acids and bases experiment. Take it a step further by experimenting with the carbon dioxide it produces. (Don’t be afraid of fire in the science
Stand on a pile of paper cups.
Combine physics and engineering and challenge 8th grade science students to create a paper cup structure that can support their weight. This is a cool project for aspiring architects.
hope this helps and have a wonderful day :)
Answer: There are few simple rules to follow.
(1) The atomic number is equal to the number of protons.
Z
= number of protons
(2) In neutrally charged elements, the number of electrons is the same as the number of protons.
Z
= number of protons = number of electrons (no charge)
Otherwise, positive charge means that the element lost an electron and negative charge means it gained an electron.
(3) The atomic mass is equal to the sum of the number of protons and number of neutrons.
A
= number of protons + number neutrons
or
A
=
Z
+ number neutrons
So if you say that
Z
= 20 and
A
= 40, then
A
=
Z
+ number neutrons
40 = 20 + number of neutrons
40 - 20 = number of neutrons
Therefore,
number of neutrons = 20
Explanation:
