Geiger-Muller tube is instruments requires you test three times the background of the work area.
<u>Explanation</u>:
These detectors are gas filled detectors and hence requires time for responding to the value. This time is taken because during this period it collects the electric charges and features of the electric circuit. It also gets stabilized during this period. This device has thumb rule i.e one must wait or hold for at the least 3 times the time constant before getting the precise and accurate reading. The time constant order is 10 seconds for the ionization chamber but for the Geiger counter it can vary from seconds to greater than 20 seconds
Answer:
b) and c)
Explanation:
Greenhouse gases are gases found in the atmosphere that absorb infrared radiation and trap the sun’s heat, thereby producing an effect known as <em>greenhouse effect.</em> By this natural way, the earth is able to be kept warm at an optimal temperature, to make it habitable for humans and other organisms. These gases referred to as <em>greenhouse gases</em> include, carbon dioxide, methane, water vapour and other trace gases found in the atmosphere. Greenhouse gases could be likened to the glass in a greenhouse that helps in trapping heat to keep the greenhouse warm at optimal temperature necessary for plant growth and development.
Without this natural greenhouse effect caused by greenhouse gases, life on earth would be almost impossible as the earth would almost be covered with ice below 0 degrees Fahrenheit.
The increased level of greenhouse gases we now find in the earth’s atmosphere is responsible for the additional warming of the earth’s surface, causing an enhanced greenhouse effect which results in global warming.
Statement a) cannot be used as an explanation because it is false. Greenhouse effect makes the earth habitable.
Statement d) cannot be used as an explanation because carbon dioxide is not the only greenhouse gas that matters. Water vapour, CFC and methane also have impacts.
<em>Statement b) and c) are the best statements to use in explaining the true nature of greenhouse effect.
</em>
<span>b. a cell takes in DNA from outside the cell.</span>
Answer:
Which data help hydrologists predict floods?
Impermeable land area
Snowpack
Explanation:
Impermeable land area
, Snowpack
The above factors are very essential to an hydrologist to predict floods though other factors such as topography, drainage among others are also inclusive to make the prediction rightly.
Can you take a closer picture please.
