.................... elements are the most stable elements.

In ammonia molecule ( NH₃ ) , the number 3 refers to the number of .........................

When an acid dissolves in water, it produce .............ions.

All of these substances turn litmus paper into red except ...................

Mona bought a cup of yogurt and found the taste is sour, so she concluded that it contains a compound from ...................

The sum of reactants masses in any chemical reaction is .................... the sum of products masses.

Direct combination reaction takes place between ....................

Which of the following is considered a balanced chemical equation?

Choose the suitable diagram for a monovalent metallic element.

The type of this reaction

Elements can be classified according to their properties and electronic structure into

Elements contain less than 4 electrons in outermost energy level

Elements contain more than 4 electrons in outermost energy level

..............is the only liquid metal element

..................is the only liquid non-metal element

..........tend to lose electrons and change to positive ion during chemical reaction

..........tend to gain or share electrons and change to negative ion during chemical reaction

............... don't participate in chemical reaction due to completeness of outer most energy level with electrons

Predict the product:

Mg + N₂ → ?

Which general formula shows direct combination reaction?

What type of reaction is the following:
 $NH_3+HCl_{ }->NH_4Cl$