CH10 Chapter 2 checkup

Magnesium is the eighth most abundant element in Earth’s crust. It is a typical metallic element.

What is the chemical symbol for magnesium?

(a)  

About how many natural elements are there in total?

• About 10

• About 100

• About 1000

• About 10000

Name the table that displays all known elements in order of increasing atomic number.

(a)  

Where is magnesium found in the periodic table?

Which of the following elements can be found in the same group as magnesium?

• Beryllium

• Caesium

• Barium

• Radon

Write the electronic configuration of magnesium (atomic number 12) in shell notation.

(a)  

Match the term to its description.

• molecule

• A pure substance made up of only one type of atom, identified by its unique number of protons.

• mixture

• A combination of two or more substances that are not chemically bonded, allowing them to be separated physically.

• compound

• A group of two or more atoms bonded together, representing the smallest unit of a compound or element that can exist.

• atom

• The smallest unit of an element that retains its chemical properties, consisting of a nucleus and electrons.

• element

• A substance formed when two or more different elements chemically bond together in fixed proportions.

Organise these options into the right categories

Groups:

(a) Proton

,

(b) Neutron

,

(c) Electron

• Number can vary to form different isotopes.

• count = nucleon no. - proton no.

• Has a negative charge.

• Has the same mass as a neutron

• Has a positive charge.

• Mass ≈ 0 amu (very small)

• Has the same mass as a proton

• Not found in the nucleus.

• Has no charge.

• Determines the element identity.

Match the atoms to their neutron count.

• 60

• 
• 34

• 
• 146

• 
• 1

• 

Match the following

• Al

• Noble gas

• Ne

• Found in group 3

• Mg

• Has 2 valence electrons

• N

• Electron configuration is 2, 6

• O

• Atomic no. 7