Answer:
The answer is C
Explanation:
A: protons
B:electrons
C:neutrons
D:quarks
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2: If the atomic number of an element is 16, then it has 16 electrons.
True
False
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3: An unknown substance is tested and found to have the following physical properties:
brittle
fair conductor of electricity
dull (not shiny)
The substance is most likely a _____.
A:metal
B:metalloid
C:nonmetal
D:can not be determined without more data
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1)Protons and Neutrons have approximately equal masses
2)TRUE
3) B-Metalloid
Answer:
its a and b
Explanation:
i got it right on test
Answer:
An official Olympic Sized pool is 50 meters long by 25 meters wide.
Explanation:
Answer:
Explanation:
A chemical change, as the name suggests, must result from a change in the chemical makeup and new substances are produced. A very common example is metal rusting.
A physical change can be observed without a change in chemical composition. No new substances are produces. Ripping paper and an ice cube melting are physical changes.
A rubber band stretching is a physical change. No new substances are made and the chemical makeup remains the same.
Answer:
physical
Explanation:
this is a physical action to create a change. does not involve chemicals or elements
concentration of O₂ dissolved in H₂O can be written as ppm
ppm stands for parts per million - mg/kg
the amount of mg in 1 kg of solution
the mass of O₂ - 0.008 g
1000 mg equivalent to 1 g
therefore mass of O₂ in mg - 0.008 g x 1000 mg/g = 8 mg
the mass of water is 1000 g
1000 g is equivalent to 1 kg
mass of water in kg - 1000 g / 1000 g/kg = 1 kg
there's 8 mg of O₂ in 1 kg of water
therefore concentration of O₂ is - 8 mg/kg
also can be written as 8 ppm
answer is 8 ppm
Answer : The concentration of in parts per million is, 8 ppm
Solution : Given,
Mass of oxygen gas (solute) = 0.008 g
Mass of water (solvent) = 1000 g
First we have to calculate the mass of solution.
Mass of solution = Mass of solute + Mass of solvent = 0.008 + 1000 = 1000.008 g
Now we have to calculate the concentration of in parts per million.
ppm : It is defined as the mass of solute present in one million parts by mass of the solution.
Now put all the given values in this expression, we get
Therefore, the concentration of in parts per million is, 8 ppm
b. solvent.
c. dissolved medium.
d. none of the above