The recommended daily requirement of calcium is1,000 mg. Tap water in a Midwestern city contains approximately 150 mgCa/L. A person living in the city who drinks two liters of water in oneday would receive ________ percent of his/her RDA of calcium. A. 3
B. 7.5
C. 15
D. 30

Answers

Answer 1
Answer:

The answer is D. 30 percent


Related Questions

Describe the general location of the electrons in a covalent bond
Which of the following an inorganic compound?CH3(CH2)3CH3 pentaneC6H12O6 glucoseC4H10 butaneH2O water molecule
How does a prokaryotic cell know how to reproduce? A The instructions necessary are found in the nucleoid. B A hormone is released that prompts a mature cell to mate. C An enzyme reacts with the cytoplasm to create two cells from one. D The DNA in the nucleus provides the instructions to the cell.
Match the separation techniques with the correct descriptions. 1. Heating a solid until it passes directly from the solid phase into the gaseous phase. 2. Separating a liquid from an insoluble solid sediment by carefully pouring the liquid from the solid without disturbing the solid. 3. The process of vapor returning to the solid phase without a liquid phase in between. 4. Heating a mixture to vaporize a volatile liquid component to make the remaining component dry. 5. Separating a solid from a liquid using a porous material, such as paper, charcoal, or sand, as a filter. 6. Using a solvent to selectively dissolve one or more components from a solid mixture.A. SublimationB. Solids that SublimeC. ExtractionD. DecantationE. EvaporationF. Filtration
What two forces act in the nucleus to create a 'nuclear tug of war'?

1)What is not true of a scientific law?A) It must be verified by scientists around the world.
B) It attempts to explain why things happen.
C) It describes what happens in the world around us.
D) It must be supported by many independent scientific investigations.

2)Observation and experimentation have led many scientists to accept a theory about the origin of the universe. This theory is called the Big Bang Theory. Scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. What makes this a scientific theory?

A)It has been proven by several scientists independently, resulting in its being accepted as truth.
B)It is based on the beliefs and opinions of the majority of the scientific community.
C)It is an observation of the natural world that has been proven as fact.
D)It is the best explanation that scientists can offer, based on many scientific investigations.

3)A scientist in Italy published his findings from a scientific investigation that he conducted. Other scientists from around the world conducted similar investigations to test the results. All of the investigations result in similar findings. What does this say about the findings of these investigations?

A)They have been proven to be scientific fact because all the investigations gave similar findings.
B)The findings are automatically promoted to a law because they were proven by so many scientists.
C)They are ready to be published in the media and in text books as a new scientific theory.
D)The results are considered more reliable because they were documented by separate investigations.

4)Which of the following is not an example of kinetic energy?

A)mechanical energy
B)nuclear energy
C)electrical energy
D)thermal energy

Answers

A) It must be verified by scientists around the world.

A scientific law is a way to describe a phenomenon that occurs in our universe. In order for a research to become law, it must be accepcted by the vast majority - if not all - of the scientists in the same field. However, they do not have to verify the potential law, they can choose to falsify or just to accept proofs taken by the discovers.

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A)It has been proven by several scientists independently, resulting in its being accepted as truth.

The Big bang is a scientific theory that explain how our universe was born. Before becoming a theory and becoming the "fact" we assume it is, it was long subject of study, and it was accepted only when different study from different scientists pointed out in the same direction. Hoever, ever today, study continues to have a better understanding of the phenomenon.

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D)The results are considered more reliable because they were documented by separate investigations.

When different experiments are made, and they gave out similar results, the results become more reliable, as they are been proven by different sources in an indipendent way. However, this do not imply a pubblication or the trasformation of the results into a scientific law, as those steps go through a different process.

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B)nuclear energy

C)electrical energy

D)thermal energy

Only mechanical energy is a type of kinetic energy. Kinetic energy means an energy that derives from a movement. Nuclear energy, electrical energy and thermal energy are other forms of energy. Energy from one of these sources could be converted into kinetic energy, or kinetic energy could be used to generate other forms of energy.

1)What is not true of a scientific law?
C) It describes what happens in the world around us.


2)Observation and experimentation have led many scientists to accept a theory about the origin of the universe. This theory is called the Big Bang Theory. Scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. What makes this a scientific theory?

D)It is the best explanation that scientists can offer, based on many scientific investigations.

3)A scientist in Italy published his findings from a scientific investigation that he conducted. Other scientists from around the world conducted similar investigations to test the results. All of the investigations result in similar findings. What does this say about the findings of these investigations?

A)They have been proven to be scientific fact because all the investigations gave similar findings.

4)Which of the following is not an example of kinetic energy?

A)mechanical energy

Which formula represents a nonpolar molecule?
(1) HCl (3) NH3
(2) H2O (4) CH4

Answers

Answer:

(4) CH4

Explanation:

When there are no polar bonds in a molecule, there is no permanent charge difference between one part of the molecule and another, and the molecule is nonpolar.

In option A, HCl is not nonpolar because Cl has a pretty high electronegativity of 3.16, the H-Cl bond is polar due to the electronegative difference. This means option A is wrong.

In option B, A water molecule is polar because (1) its O-H bonds are significantly polar, and (2) its bent geometry makes the distribution of those polar bonds asymmetrical. The side of the water molecule containing the more electronegative oxygen atom is partially negative, and the side of the molecule containing the less electronegative hydrogen atoms is partially positive.

In option C, NH3 is polar because it has 3 dipoles that do not cancel out. Each N-H bond is polar because N is more electronegative than H. NH3 is overall asymmetrical in its VSEPR shape, so the dipoles don't cancel out and it is therefore polar.

In option D, CH4 looks like a C in the middle with 4 H's coming off of it. It is nonpolar because the electronegative difference is balanced. The H's all have the same electronegativities, and all cancel out since they are opposite one another.

The answer to this is (4), or CH4
This is because CH4 is both symmetrical in its molecular format and also does not have any lone pairs.
Because of that, the charges on it are balanced, and if all charges are balanced, it means that the molecule is non-polar

Answer: (4) CH4

Hope this helped!! :D

Compounds that are formed when two or more atoms combine to form molecules are called?

Answers

When two or more atoms of the same elements combine to form molecules of a compound, the compound formed is said to be molecular.

Two atoms of an element can become chemicallybonded to form a molecular compound.

For example, two atoms of oxygen combine, the result would be a molecule of oxygen. Two atoms of chlorine combining will result in a molecule of chlorine.

When the combination is that of atoms of different elements, what will result is an ordinary compound.

More on molecular compounds can be found here: brainly.com/question/25228419?referrer=searchResults

Compounds that are formed when two or more atoms combine to form molecules are called Molecular Compounds.

An example of a good thermal conductor

Answers

Examples of good thermal conductors are gold,silver and diamond
The best thermal conductors are generally metals and take the shape of pans, appliances, pipes and other commercial and residential fixtures.

All of the following need to be present for a plant to do photosynthesis except light

water

oxygen

carbon dioxide

Answers

Oxygen is a by-product of photosynthesis thus it is not needed for photosynthesis to occur.  

Light is needed to provide the energy needed as photosynthesis is endothermic and is also needed to ionise the water molecule to get hydroxide and hydrogen ions and carbon dioxide is what is reduced to starch.

If 10.3 g of Mg3N2 is treated with water, what volume of gas would be collected at STP

Answers

Use the ideal gas law: PV=nRtTo find volume, move to V=(nRt)/PN=# of moles (to find, 10.3 g/100.929g)=.102 molesR=ideal gas constant(this value is 0.082056(Liters*atmospheres)/(Kelvin*mol)T= temp which at stp is 273 KelvinP= 1 atmosphereV=((.102 moles)(0.082056 Latm/Kmol)(273 K))/1 atm
Mg3N2 +6H2O → 3Mg(OH)2 +2 NH3
relative weight of Mg3N2 = (3x24)+(2x14) = 100 g/mole
mole of Mg3N2 = 10,3 g/100 g/mole = 0,103 mole
mole of NH3(g) = 2/1 x 0,103 mole = 0,206 mole
volume NH3(g) which collected at STP = mole NH3(g) x 22,4 litre/mole = 0,206 mole x 22,4 litre/mole = 4,6144 litre.