Grade 8

Meteors are formed in ........ layer

• Mesosphere

• Stratosphere

• Thermosphere

• Troposphere

The element whose atomic number 15 is similar in its chemical properties to that the atomic number......

• 5

• 7

• 17

• 18

.......... is from microfossils

• Fern

• Mammoth

• Formnefira

• Dinosaur

All the following are greenhouse gases except ........

• CO²

• O²

• N²Ò

• CH⁴

P block contains...... group

• 10

• 2

• 6

• 8

The ........ replace the wood material part by part of an old trees

• Silver

• Silica

• Iron

• Wood

Give reasons for :

1 - the presence of hydrogen bond between water molecules

Give reasons:

Potassium is more active than sodium

Give reasons:

Water is polar compound

Give one example:

1- endangered plant