Elements and compound

Scientists have discovered ___ different kinds of atoms [elements] that occur naturally in the universe.

• 24

• 118

• 94

• 110

A group of atoms joined tightly together chemically is called ____

• molecule

• mixture

• solution

• Alloy

Elements are arranged in the periodic table. it is organised in rows and columns. The rows are called ___

• column

• group

• period

• horizontal

Chemical Symbol of sodium

• Na

• NA

• S

• Sd

P is a chemical symbol of _____

• Potassium

• Phosphorus

• powder

• boron

which subatomic particle has positive charge?

• Electron

• Proton

• neutron

• nucleus

water molecule is made up ___ elements

• 3

• 2

• 4

• 5

These are made up of same type of atoms.

• Mixture

• Element

• Compound

• Alloy

Which elements combine together to make magnesium chloride?

• hydrogen and chlorine

• magnesium and chlorine

• magnesium, oxyden and chlorine

• magnesium, chlorine and oxyden

Number of proton in an atom is called _____

• Atomic number

• atomic mass

• chemical symbol

• chemical formula