Question

1. distinguish compare and contrast the elements and compounds in terms of their chemical symbols and chemical formulas. which are elements, and which are compounds? ar, ch₄, h₂so₄, hg, i₂, kno₃, sio₂

Explanation:

Step1: Recall element and compound definitions

Elements are pure substances made of only one - type of atom. Compounds are made of two or more different types of atoms chemically combined.

Step2: Analyze each chemical symbol/formula

• $Ar$ (argon) is an element as it consists of only argon atoms.
• $CH_4$ (methane) is a compound as it is made of carbon and hydrogen atoms.
• $H_2SO_4$ (sulfuric acid) is a compound as it contains hydrogen, sulfur, and oxygen atoms.
• $Hg$ (mercury) is an element as it consists of only mercury atoms.
• $I_2$ (iodine) is an element as it consists of only iodine atoms.
• $KNO_3$ (potassium nitrate) is a compound as it contains potassium, nitrogen, and oxygen atoms.
• $SiO_2$ (silicon dioxide) is a compound as it contains silicon and oxygen atoms.

Answer:

Elements: $Ar$, $Hg$, $I_2$
Compounds: $CH_4$, $H_2SO_4$, $KNO_3$, $SiO_2$