What is the name of 7A group and zero group?

Find the atomic number for the following elements.

(1) Element X lies in the first period and zero group -------------

(2) Element Y lies in the second period and 3A group -------------

(3) Element Z lies in the third period and 7A group ------------

What is the scientific base on which the modern periodic table classified?

Locate the position of the following elements in the modern

periodic table:

₁₀ Ne

₁₁Na

₁₃ AI.

₂₀Ca

₁₈ Ar

The scientist Mendeleev arranged the elements ascendingly according to-----------while the scientist Moseley arranged them ascendingly according to ------------

The modern periodic table consists of-------horizontal periods---------- vertical groups.

What is meant by elements have some properties of metals and non metal

What is meant by Chemical activity series

Explain the behavior of the following elements with water:

(1) Silver

(2) Potassium...

the balanced chemical equations which express reaction of:

(1 ) Carbon dioxide with water.

(2) Magnesium with dil. hydrochloric acid

Each period in the modern periodic table starts with --------- element.

When sodium reacts with water --------- gas evolves

GR: Elements of group (1A) are known as alkali metal.

GR: Liquefied nitrogen is used in preservation of cornea of the eye.

give one example for :

(a) Inert gases

(b) Alkali metals.

(c) Halogens.

The most active metal --------------

The most active nonmetal --------------

Mention one use for each of the following:

(1) Liquid sodium

(2) Silicon

(3) Cobalt 60

Why lithium is not kept under kerosene but it is kept under paraffin oil?

GR: Presence of hydrogen bond between water molecules.

Give reasons for Pure water doesn't affect litmus paper dye.

Give reasons for: Although sugar is a covalent compound, it dissolves in water.

What are the results of ?

(1) Water is polluted by the wastes of Man and animal.

What are the results of ?

Storing water in plastic bottles of mineral water.

---------- cause Death of brain cells.

------------ cause Cancer of liver

---------- cause Blindness.

Sodium oxide from ------------ oxides.

The strongest metal lies in the ---------- group.

What is meant by ?

Chemical activity series?

What is meant by ?

Water pollution

What is the importance of ?

Sodium in liquid state.

Water:

GR: The use of radioactive Co 60 in food preservation.

GR: Elements of the same group have similar properties.

GR: The boiling point of water is high.

GR: Alkali metals are kept under kerosene in the lab.

What is the effect of the following on the water environment?

Drainage of factories wastes in rivers and seas.

What is the effect of the following on the water environment?

Using of rivers and seas water as a renewable source for cooling the nuclear reactor.

What is the effect of the following on the water environment?

Mixing of animal and Man wastes with water.

GR: The lower part of the stratosphere is suitable for flying airplanes.

GR: Ionosphere is important for radio stations.

Mention the importance of each of the following:

Van Allen's Belts

Altimeter

Satellites

What is meant by each of the following?

Atmospheric pressure.

The aurora phenomenon.

The highest in temperature ----------- layer .

The least in temperature --------- layer

Replace each of the following statements by a suitable scientific term :

1) The boundary separating between stratosphere and mesosphere where temperature is rather constant.

2) Charged layer reflects radio waves.

Replace each of the following statements by a suitable scientific term :

3) One of the atmosphere components that its ratio increased in recent years to reach about 0.038%.

4) A type of ultraviolet radiation that is absorbed completely (100%) in the Ozone Layer.

Most of weather features occur in ............ layer whereas satellites rotate through the

............. layer.

Ultraviolet radiation has a ----------effect, and the infrared radiation has a ---------effect.

Among the pollutants of the Ozone Layer are------------ compounds that are used in air conditioning sets and ---------- compounds that are used in fire extinguishers.

Illustrate with formulas only the role of ultraviolet radiation in the formation of Ozone gas.

An aero plane captain announced atmospheric pressure outside the aero plane is 90 millibar. In which layer of the atmosphere was the plane flying? Why?

molecule is formed from combining an atom of an element to a molecule of the same element

----------------------------

Continuous increase of the average temperature of the air near the surface of the Earth.

Ozone Layer is measured by a unit called -----------

---------------are greenhouse gases

Give reasons for:

Formation of Ozone Layer in the stratosphere.

GR; Stop Producing concord airplanes.

Fossils of old organisms that lived in the past for a certain period and then became extinct.

---------------------------------

Replacing, part by part, the wood material of trees by silica to form woods.

----------------------

Remains or traces of organisms that lived in the past and were preserved in sedimentary rocks.

---------------------------

Archaeopteryx represents the link between----------- and -------------

Fossils are used in exploration and determining the age of ---------

----------- is an example of microfossils

Complete fossils of insects are found preserved in -----------

Mention the importance of each of the following:

(1) Coral fossil

(2) Nummulites fossil

Give reasons for.

Naming the petrified forests with wood mountain.

Give reasons for.

El-Mokattam's mountain was once a sea floor more than 35 million years ago.

----------- indicate(s) extinction.

The death of all members of species of living organisms called --------------

Explain the effect of extinction of a species of living organisms on:

(1) Simple ecosystem

(2) Complicated ecosystem.

Exclude the unsuitable word and mention what the rest has in common:

(1) Dodo / Quagga/ Bald eagle / Mommouth

(2) Panda /Rhinoceros / Quagga / Bald eagle