are all subtances pure?? and how do metals and non metals react with oxygen and hydroxides

are all subtances pure??
and how do metals and non metals react with oxygen and hydroxides


2 Answers

25757 Points
3 years ago
Metals react with water and produce a metal oxide and hydrogen gas. Metal oxides that are soluble in water dissolve in it to further form metal hydroxide. But all metals do not react with water. Metals like potassium and sodium react violently with cold water.
Vikas TU
14149 Points
3 years ago
Dear student 
Here is the ans for question number 2 
The reaction of metal and non-metal with oxygen is shown as follows
 metal + oxygen ------> metal oxide 
 example 2Mg + O2 -------> 2MgO
 non-metal + oxygen ------> non-metallic oxide
 S + O2 ------> SO2
 metal + water  -----> metal hydroxide + hydrogen gas
 2Na + 2H2O -----> 2NaOH + H2
Generally non-metals do not react with water
2) Function  of 
a) Nucleus
The nucleus in the center body of the cell. It stores the cell 's DNA and coordinates cellular activity and processes.
b) Cell Wall
Cell wall performs various functions like
Structural support to the cell
Protection from external environment
Checks entry of various substances entering and leaving the cell
Maintaining the shape of the cell.
c) Plastids
Plastids are major organelles found in plant cells and algae. There are three major types of plastids, namely chromoplasts, leucoplasts and chloroplasts.
Chromoplast- Chromoplasts are coloured plastids,containing coloured pigments like carotene (orange), xanthophylls (yellow) etc. These pigments are responsible for the colour of plants.
Leucoplast:- These are white or colourless plastids and do not contain any pigment.The leucoplasts store starch and other storage products.
Chloroplast are plastids that confer green colour to plants because of pigment chlorophyll found in plants while chromoplasts are plastids that provide distinctive colour like red, yellow etc. Chloroplasts can also turn into chromoplasts during fruit ripening.
d) Chromosomes
The important functions of the chromosomes is to control all the activities of a living cell. Chromosomes are important for the process of cell division and are responsible for the replication, division and creation of daughter cells, that contain correct sequences of DNA and proteins.
e) Cell membrane
Allows only the entry of certain solutes and water into the cell. It thus checks the entry and exit of various material into the cell.
3) Tips for saving petroleum
The best method to save petrol is to use it judiciously. We should increase the use of alternate sources of fuels like CNG, which also produce less smoke than petrol. Small steps like using more of public transport instead of personal transport also help a great deal in saving petroleum. 
4) We should minimise the use of fossil fuels because these are non-renewable resources of energy with limited reserves. In other words, these resources will vanish very soon if not used properly. Also, some of the fossil fuels produce lot of smoke on burning and thus lead to pollution.

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