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Science
The observation, identification, description, experimental investigation, and theoretical explanation of phenomena is all part of science. Nothing is immune to the scientific process: from charm quarks that haven't existed naturally since the beginning of time to Pluto, recently demoted from planet to dwarf planet. Questions on knowledge about the material and physical aspects of our world are asked and answered here.
203,801 Questions
Why has gold jewelry servived from thousands of years ago?
because its really low in the rective series and is hard to tarnish.
How do you change measurement from big to small?
You could change the units you are using for measuring. For example if I use feet to measure the distance to the moon, it would be very big, so I need miles or even another unit of measurement. Scientific notation helps too.
Do plants need sugar in fertilizers?
No, plants can make their own sugars by photosynthesis. The purpose of fertilizers is to provide elements such as nitrogen which the plant cannot take in from air or water.
When is esd protective area signs not requried at the entrance to esd control work area?
For not needing at least one sign at the entrance of an ESD protected area, the answer likely is never. The issue is how do all people, including visitors, know that it is an EPA, and that special precautions are required including grounding all conductors including people.
The ESD Association document specifying requirements for ESD control programs is ANSI/ESD S20.20. It says "Caution signs indicating the existence of the EPA shall be posted and clearly visible to personnel prior to entry to the EPA." [ANSI/ESD S20.20 section 8.3]
There is also a 130 page ESD Handbook ESD TR20.20 to provide guidance.
"Appropriate signs and markings must identify protected areas so that all people entering the area, including visitors, are aware that special precautions are needed. Packaging and containers that enter the protected area must be approved for use based on the expected movement within the protected area. Transportation of sensitive items between protected areas or to unknown or uncontrolled destinations may require higher levels of static protection."
There is an example of an EPA Caution Sign per ESD TR20.20-2008 Figure 18 "Example of an EPA Caution Sign", the text is "Caution, ESD Protective Area, Use Electrostatic Discharge Protective Handling Procedures"
What is the area of the quadrilateral with vertices at 8 9 and 1 9 and 10 3 and 1 3?
The 4 sided quadrilateral will form a right angled trapezoid when plotted on the Cartesian plane with parallel sides of 7 units and 9 units with a height of 6 units.
Area of trapezoid: 0.5*(7+9)*6 = 48 square units.
Why do people say that chemistry is very mathematical if it has more concepts than math?
It is probably to emphasise the fact that chemistry is not a purely practical subject. There can be a misconception that chemistry is mostly mixing chemicals and seeing what happens. However chemists use mathematics routinely as part of their science. However this is not unique to chemistry. All science is very mathematical.
How do you get your entomology degree?
go to college and study entomology or biology. With both you can become an entomologist.
How many vertices would a pyramid with a 9 sided base have?
Ten. Nine from the base, and one where they all meet.
Give example of store roots and their roots?
Since this ended up in the Mathematics section, there is an outside chance you meant to write square root.
The square root of 9 is 3.
The square root of 25 is 5.
If you didn't mean to write square root, please resubmit your question and direct it to the proper section.
What formula do you use for a triangular object?
This depends what you are trying to work out, and what kind of triangle you have.
What are four charactoristics of eubacteria?
eubacteria lack a nucleus, lack histones in their DNA, have no membrane bound organelles, and their DNA is in a circular form.
