which of the following statements about ph is true?

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The 4 most common elements in living organisms areC,H,O,N
Which of the following is a trace element in the human bodyZinc
Which of the following statements regarding matter is falseAll matter exists in the form of compounds
Which of the following statements best describes a compoundA compound contains two or more different elements in a fixed ratio
In the equation 2H2 +O2- - -2H2OOnly H2O is a compound
Which of the following trace elements needed by humans is commonly added table saltIodine
In some areas fluoride is added during the municipal water treatment process in order to helpReduce tooth decay
Which of the following particles is found in the nucleus of an atomProtons and neutrons
Electrons move about the nucleus of an atom in the same way thatInsects fly around a bright lamp at night
What is the atomic mass of an atom that has 6 protons 6 neutrons and 6 electrons12
And uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many electrons does boron have?5
Which of the following is another term used for atomic massDalton
The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium?23
Which of the following best describes the atomic number of an atom?The number of protons in the atom
Typically nitrogen atoms are composed of electrons protons and neutrons and isotope of nitrogen couldHave more neutrons then the usual nitrogen atom
A radioactive isotope is an isotope thatDecays
If you found a fossilized dinosaur bone what method could be used to determine the age of the fossilIsotope analysis
Which of the following statements about radioactive isotopes is trueThe energy emitted by radioactive isotopes can break chemical bonds and cause molecular damage in cells
Radioactive isotopesCan be used in conjunction with PET scans to diagnose diseases
When full the innermost electron shell of argon gone contains (blank) electrons and the outermost shell contains (blank) electrons2. And 8.
What happens to an atom if the electrons in the outershell are alteredThe properties of The atom will change
A(n) blank forms when two atoms share electronsCovalent bond
A hydrogen atom has one electron how many covalent bonds can hydrogen formOne covalent bond
Table salt is formed whenSodium donates it's single outer electron to chlorine
The body uses atoms in different ways to accomplish different tasks for example one portion of the body of discounts him supply strengthens bones whereas another portion combines with proteins to stimulate blood clotting after tissue injury which is the same as the follow provides the most logical chemical explanation of calcium's ability to perform such different functionsThe bone contains calcium salts which are less reactive than the calcium ions found in the blood
Medicines are often administered in pill form in many cases the active ingredient of the pill (the drug) is joined to another substance by (blank) this forms a (blank) which is stable in the dry environment of the pill bottle that does but disassociates under the wet conditions of the digestive system to release the drugs in the bodyIonic bonds and salt
What is the fundamental difference between covalent and ionic bonding.In a covalent bond the partners share a pair of electrons in an iconic bond one partner accepts electrons from the other
Which of the following statements regarding the oxygen atom of a water molecule is trueOxygen is more electronegative than the hydrogen atoms
In a water molecule hydrogen and oxygen are held together by a (blank) bondPolar covalent
A water molecule H (blank) O (blank) H is held together byTwo polar covalent bonds
The hydrogen atoms of a water molecule are bonded to the oxygen atom by (blank) bonds whereas neighboring water molecules are held together by (blank) bondsPolar covalent and hydrogen
(Blank) are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bonds within and around large moleculeHydrogen bonds
Water molecules stick to other water molecules becauseHydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules
Which is the following statements regarding chemical reactions is falseSome chemical reactions create electrons others destroy them
In the equation 2 H2 +02 arrow 2 H2O the H2 molecules are (blank) and H2O molecules are (blank)Reactants and products
Photosynthesis requires many steps to make glucose as a result of the synthesis processAll carbons from the six carbon dioxide atoms are found in glucose
The tendency of water molecules to stick together is referred to asCohesion
Water's surface tension and heat storage capacity is accounted for by it'sHydrogen bonds
The temperature of the evaporation is much higher for water them for alcohol without knowing more about the chemistry of alcohol which of the following is the most logical chemical explanation for this phenomenonFewer hydrogen bonds formed between Alcohol molecules as a result less heat is needed for alcohol molecules to break away from solution and into the air
As ice meltsHydrogen bonds are broken
Which of the following statements about water is falseIce is more dense than liquid water
You made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon of sugar and a cup of hot water which of the following statements is trueYou've just prepared an aqueous solution
Which of the following is dependent on the ability of water molecules to form hydrogen bonds with other molecules besides waterThe universality of water as a solvent
Clot formation in our blood can lead to a heart attack or stroke what was altered in the proteins that made the clotThe proteins were no longer soluble in blood
A pharmaceutical company hires the chemist to analyze the purity of the water being used and it's drug preparation if the water is pure the chemist would expect to findH2O molecules H+ ions and OH- ions
A solution with a pH of 7 isNeutral
Compared to a solution of pH 3 a solution of pH 1 is100 times more acidic
Which of the following statements about pH trueAn increase in hydrogen ion concentration means a decrease in pH scale units
Household ammonia has a pH of 12 household bleach has a pH of 13 which of the following statements about them is trueThe ammonia has 10 times as many H+ ions as the bleach
A bufferDonates H + ions when conditions become too basic and accepts H +ions when conditions become to acidic
A diabetic who does is not utilized insulin properly will Metabolize fats instead of glucose a condition called diabetic keto acidosis is a common result of excessive fat metabolism causing blood pH values of 7.1 or less what has happened to the blood pH and whyThe pH is below normal (acidic) because the buffering capacity was exceeded
What's at the following statements about acid precipitation is falseAcid precipitation has little or no effect on soil chemistry
The omission of (blank) and (blank) are primarily responsible for acid precipitationNitrogen oxides and sulfur oxides
Which of the following would be considered an effective way to decrease the production of acid precipitationWhenever possible walk or ride a bicycle instead of driving a car
Which of the following hypotheses would be supported if liquid water were found on Mars and contained evidence of bacterial like organismsThe chemical evolution of life is possible
What change is occurring in this figureChlorine is filling it's third electron shell
The hydrogen bonds shown in this figure are eachBetween oxygen and hydrogen atom of different water molecules
After reading the paragraph answer the questions that followYou've been experiencing acid indigestion lately and you'd like a quick fix for the problem. You do a little research on Internet and discover that your problem is caused by excess stomach acid. In the pharmacy Aisle however you're having a little trouble deciding what to purchase to address the problem. At the pharmacy counter the clerk recommends that you purchase Pepcid AC or Alka-Seltzer tablet.
If you could check the pH of the recommended tablets you would expect it to beHigher than 7
If you were able to chemically analyze your stomach fluids 30 minutes after taking two tablets you would findFewer hydrogen ions
which of
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