
Ore is a deposit in Earth's crust of one or more valuable minerals. The most valuable ore deposits contain metals crucial to industry and trade, like copper, gold, and iron. Copper ore is mined for a variety of industrial uses. Copper, an excellent conductor of electricity, is used as electrical wire.
Answer:
The correct option is: stable environment
Explanation:
According to the Darwin's theory, natural selection is the concept by which all the small useful variations of traits are preserved.
According to Darwin, there are three <u>necessary and sufficient conditions</u> for the occurrence of natural selection:
1. struggle for existence
2. variation
3. inheritance
These conditions are said to be necessary because if these conditions are not satisfied then natural selection does not occur.
These conditions are said to be sufficient because if these conditions are satisfied, then natural selection will most definitely occur.
Answer:
experiment can show the movement of pollutants through the groundwater!
Explanation:
Answer: The correct option is A.
Explanation: The given molecules are the molecules of same element.
These molecules are considered as diatomic species.
Polar molecules are the molecules in which some polarity is present in the bond. These molecules are formed when there is some difference in the electronegativities of the elements. Example: HCl
Non-polar molecules are the molecules where no polarity is present in the bond. These molecules are formed when there is no difference in the electronegativities of the elements. Example: 
The given molecules are non-polar in nature.
Hence, these molecules must be non-polar. So, the correct option is A.
Answer: There are five significant figures in 865,010.
Explanation:
When a degree of accuracy is stated by each digit present in a mathematical figure then it is called a significant figure.
Rules for counting significant figures is as follows.
- Any non-zero digits and zeros present between a non-zero figure are counted. For example, 3580009 has seven significant figures.
- Trailing zeros are counted in a non-zero figure. For example, 0.00250 has three significant figures.
- Leading zeros are not counted. For example, 0.0025 has two significant figures.
So, in the given figure 865010 has five significant figures and the trailing zero will not be counted.
Thus, we can conclude that there are five significant figures in 865,010.