Answer:
D. bromine (Br)
Explanation:
Bromine is an element of halogen group.
Halogens, or "salt-formers," are located in group 17 of the periodic table. The halogens have the following properties:
1) They have low melting points and low boiling points.
2) They exist as diatomic molecules in the gas phase.
3) They have seven electrons in their outermost shell, which means they have seven valence
electrons.
4) They are highly reactive nonmetals.
5) They tend to gain electrons and form negative ions.
Thus the given properties are of Bromine.
Mass of solute = 35 grams
Mass of solution = mass of nacl + mass of water = 35.8 + 184 = 219.8 grams
Concentration = mass of Nacl x 100/mass of solution.
= 35x100/219.8 = 15.92%.
Hope this helps you.
Answer:
Yes
Explanation:
A gene pool is the sum total of all the genes(sum of alleles)of a species and population at any given time is known as gene pool.
The new species are created in nature by four mechanisms such as geographic isolation (allopatric speciation), reproductive isolation (sympatric speciation), mating behaviour (parapatric speciation).
Due to any of these factors when population acquire unique changes in their genes and enough changes have been introduced in the gene pool of the population with time, two population become distinct from each other and not able to interbreed leads to the formation of new species.
Answer:
Recycling and reuse of materials
Explanation:
One of the greatest problems facing the human population is the problem of solid waste disposal. The menace of solid waste disposal has led to the idea of landfills. Land fills are depressions on the earth surface prepared for the purpose of solid waste disposal.
The most important approach towards solid waste disposal is the idea of recycling of materials. A material can be collected after use and processed into the same material or serve as a precursor in another manufacturing process. This means that no waste is generated as the materials which are supposed to be disposed of as solid waste are processed into other useful materials. This will reduce the volume of solid wastes generated that may need to be disposed in a landfill.
Answer:
One of the main uses of the cathode ray tube is in the Cathode ray oscilloscope
Explanation:
Cathode rays are produced when a gas in an evacuated glass at very low pressure and high pressure breaks up into positive and negative ions. the negative ions move towards the anode(positive electrode) while the positive ions move towards the cathode(negative electrode), and there they knock off electrons (which are known as cathode rays) from the metal plate of the cathode.
Cathode ray tubes are mainly used in oscilloscopes, television picture tubes and in computer screens.
The cathode ray oscilloscope is used in a.c. and d.c. voltage measurements, observation of waveforms, time measurements, etc.
