Answer:
Technetium. It is only found in the stars.
Explanation:
Sorry, but thats all I could find for tou
The are many elements which are not present in human body. But almost all the discovered elements are there in the universe. But the one which is not present in earth and air is technetium
What is an technetium ?Technetium is the first synthesized element by man in 1937. Technetium has no stable isotopes and it is not found in earth. But it is present in stars. However, rare earth elements such as promethium , francium etc. can be prepared or observed from uranium ores.
There are many elements especially some actinides and lanthanides which are not present in earth naturally existence on starts and other planets.
Human body is made of various elements including carbon, oxygen, nitrogen, various metals like iron, zinc etc. Various enzymes contains different elements but the number of elements which are in the surroundings of human and not inside is larger.
Therefore, all the discovered elements are found in the universe and some them are not present in earth.
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What percentage of the Periodic Table of Elements is Metals?
80 percent
About 80 percent of the elements are metals (shiny elements that conduct heat and electricity well), and 15 percent of the elements are nonmetals (poor conductors of heat and electricity). The remaining elements are metalloids, which share properties of both metals and nonmetals.
Answer:
80% of the Periodic Table consists of metals and 15% non-metals and 5% other elements.
Explanation:
what object has a mass of 10 grams and a volume of 2 mL
Answer:
Destiny = 5 g/ml
Explanation:
The formula for density is d=
Knowing this, divide your mass by volume:
10 g / 2 ml = 5 g/ml
Final answer:
Destiny = 5 g/ml
Describe a method you could use to carry out paper chromatography.
paper chromatography, in analytical chemistry, technique for separating dissolved chemical substances by taking advantage of their different rates of migration across sheets of paper..The method consists of applying the test solution or sample as a spot near one corner of a sheet of filter paper.
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which is the correct formula for the compound dinitrogen monoxide?
Answer: Dinitrogen Monoxide ( also called nitrous oxide )
is an inorganic ( not made from living matter) compound with the chemical formula of N2O.
Explanation:
Read above
A group of students were asked to design a device that converts light energy into heat. They built a small solar oven using a tin can and aluminum foil. The device reflects light into the can, warming up its contents.
Which action would most improve the design of the solar oven?
O A. Add a mirror to reflect light away from the can.
O B. Use hand lenses to focus the light into the can.
O c. Add a fan to make sure the food is evenly warmed.
O D. Change the tin can to a box with a lid to Increase cooking space.
Answer:
answer is b
Explanation:
I think it is b. I don't know what land lenses are but focusing light on the can would heat it up more.
What type of reaction takes place when using this enzyme (endergonic or exergonic)?
lactase is the enzyme
Answer:
we do the best possible in our
How might a firefighter use chemistry?
A. Chemistry can help a firefighter plan an escape route through a
burning building
B. Chemistry can help a firefighter understand combustion and how
to put out fires.
C. Chemistry can help a firefighter understand how much of a load
the floors of a burning building can hold,
D. Chemistry can help a firefighter plan an exercise routine to prepare
for fires
Answer:
me has answer
Explanation:
b
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chemistry, giving brainliest !
Answer:
20.03g
Explanation:
This is the formula for percentage yield:
Percentage yield = Actual Yield / Theoretical yield
Rearrange it to get the Actual yield, which would be:
Actual yield = Percentage yield (in decimal form) x Theoretical yield
We know that 75% of CO2 is produced as the percentage yield in a reaction and the theoretical yield for the mass we're supposed to find is 26.7 grams.
Percentage yield in decimal form: 0.75
Theoretical yield: 26.7g
Plug it in the equation
Actual yield = 0.75 x 26.7g
Actual yield = 20.03g
Some tomato ketchup accidentally got onto a piece of white fabric. Your mother suggested that lemon juice, baking soda, or vinegar would be good for removing the tomato stain. Plan and design an experiment that can be used to investigate which of the three substances is most effective in removing the tomato stain.
1. Write a hypothesis for your investigation
2. Identify the dependent, independent, and controlled variables.
3. Outline a proposed method for the experiment you would conduct.
4. What data would be collected? Suggest a suitable way(s) for recording your data.
5. Identify ONE (1) possible source of error and ONE (1) precaution.
Please if you see this help me answer these questions.
Answer:
3... uhm I'm not sure it could 2
which bond shown are triple bonds
Answer:
Hey mate.....
Explanation:
This is ur answer.....
A triple bond is made of two pi bonds and one sigma bond. Examples of compounds with triple bonds include nitrogen gas, the cyanide ion, acetylene and carbon monoxide.
Hope it helps!
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Which elements are the most reactive and why?
Answer:
Fluorine is identified as the most reactive nonmetal and the most electro-negative element in the periodic table, making it the strongest oxidizing agent. Caesium is the most reactive metal in the periodic table, so much that working with this metal often ends in explosions!
Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements.
Hope that helps.
why does hydrogen fluoride have a high boiling point
The intermolecular bonding for HF is van der Waals, whereas for HCL, the intermolecular bonding is hydrogen. Since the van der Waals bond is stronger than hydrogen, HF will have a higher boiling temperature. Since the covalent bond is stronger than van der Waals, HF will have a higher boiling temperature.
which compound contains both ionic and covalent bonds
Answer:
Any compound that contains a metal ion and a polyatomic ion would work. Polyatomic ions are covalently bonded non-metals that have some overall charge. Examples of common polyatomic ions include OH⁻ (hydroxide), NH₄⁺ (ammonium), and NO₃⁻ (nitrate). So answers to this question can be something like KOH (potassium hydroxide), but really, anything works if it contains a metal ion and a polyatomic ion.
give explanation ~~
Why are cloudy nights warmer than clear nights?
a) how many moles of o2 are needed to burn 1.50 mol of c8h18?
Answer:
Moles of oxygen needed to burn given amount of octane is 16.875 moles.
Explanation:
What is the purpose of an indicator in a titration.
Answer:
The role of indicator in titration is to detect the endpoint of the titration. When the colour of the solution changes, it indicates that the concentration of the chemical specie has reached a critical range. This change in colour is possible with the help of indicators.
Explanation:
hope it helps
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correct me if I'm wrong and if correct brainliest me please
according to iupac nomeclature rules which set of chemical name and formula for the same compound is correct?
Answer:
stock and traditional
Explanation:
the iupac says so
Melting gold with other metals makes 10-karat gold. Which term best describes 10-karat gold?
homogeneous mixture
compound
heterogeneous mixture
pure substance
Answer: a
Explanation:
Gold is known to be an element. The term that best describes 10-karat gold is that it is an homogeneous mixture.
Gold as an element of often has an ideal state of purity where there contains nothing but gold atoms.
A heterogeneous mixture is known to be a mixture that cannot be chemically sound everytime. Gold jewelry is known to be a homogeneous mixture as it is always will look good and remain unchanged for a long time.
As good example of homogeneous products, e.g a 1-kilogram 24-karat gold bar has unique properties.
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HOW DO THE FOLLOWING COMPARE IN THE AMOUNT OF ALCOHOL THEY CONTAIN: 12 OZ. BEER(5% ALCOHOL), 12 OZ. WINE COOLER(5% ALCOHOL), 1 1/2 OZ. OF 80 PROOF LIQUOR, 5 OZ. OF WINE(12% ALCOHOL)?
The amount of alcohol contained in each of the listed beverages can be compared as follows; 1/2 oz of 80 proof liquor > 5 oz of wine (12% alcohol) > 12 oz of wine cooler (5%alcohol) = 12 oz of beer (5%alcohol) .
A drink that contains alcohol must be an intoxicating beverage. The extent of intoxication of an alcoholic beverage depends on the amount of alcohol that the beverage contains. There are various types of alcoholic beverages as listed in the question.
The amount of alcohol contained in each of the listed beverages can be compared as follows; 1/2 oz of 80 proof liquor > 5 oz of wine (12% alcohol) > 12 oz of wine cooler (5%alcohol) = 12 oz of beer (5%alcohol) .
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rank the crystal lattice structures in order of decreasing efficiency of space in the structure.
Rank the crystal lattice structures in order of decreasing efficiency of space in the structure.
1. Simple cubic
2. Body centered cubic
3. Face centered cubic
4. Hexegonal close packed
Vinegar is an acid. Based on
what you know about the
properties of acids and bases,
which would you expect from
vinegar?
A. It should feel slippery.
B. It will release OH-in water.
C. It will release H+ in water.
Answer:
C
Explanation:
Acids contain H plus ions. When within a solution or neutralised these ions are released.
The substance which gives H+ ion are called as acid. Vinegar is an acid because it will release H+ in water. Therefore, option C is correct.
What is vinegar ?Acetic acid and water are combined to create vinegar through a two-step fermentation process. First, yeast consume any liquid derived from a plant source, such as fruits, whole grains, potatoes, or rice, and feed on the sugar or starch therein. It ferments into alcohol.
White vinegar typically contains 93–96% water and 4-7% acetic acid. It can be used to cook, bake, clean, and control weeds. It may also help with weight loss and decrease cholesterol and blood sugar levels.
The sugar is converted to ethanol (ethyl alcohol) by yeast and bacteria in a two-step fermentation process, which is followed by the production of acetic acid. Vinegar is acidic because it contains acetic acid.
Thus, option C is correct.
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What is a net ionic equation?
How did the atomic model change due to the research of thomson, rutherford, and bohr?
Answer:
Thomson's plum pudding model of the atom had negatively-charged electrons embedded within a positively-charged "soup." Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus. Based on these results, Rutherford proposed the nuclear model of the atom.
Identify the total number of molecules in the chemical formula: 6CH4 a 6 b 10 c 24 d 30
Answer: A.6
Explanation:
The total number of molecules in the chemical formula is 6
What is a molecule?
Molecules are the smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms.
The correct form of question will be:-6 molecule of methane CH₄
6CH4
a) 6 c) 10 c) 24 d) 30⇒ Number of aton of carbon is 6
⇒Number of atom of hydrogen is 24
⇒Total number of atom is 30
What is an atom ?
An atom is a particle of matter that neither be created nor be destroyed. An atom consists of a central nucleus that is usually surrounded by one or more electrons. Each electron is negatively charged. The nucleus is positively charged, and contains one or more relatively heavy particles known as protons and neutrons.
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how much water will you need to add to your working solution to get to a 100 ml total volume of a 0.03m nacl solution?
Answer:
The solution is made by adding 4.38 g NaCl to a 250-mL volumetric flask. About 100 mL of water are added and when all the NaCl dissolves water is added up ...
Which two elements have more protons per atom than phosphorus?
Answer:
nitrogen have more protons per atom than phosphorus
Oxygen and fluorine are the two elements that have more protons per atom than the element phosphorus.
What is phosphorus?Phosphorus (P), a nonmetallic chemical element of something like the nitrogen group (Group 15 [Va] of the periodic table), is a colorless, semitransparent, soft, sticky solid that glows in the dark at room temperature.
Hennig Brand, a German businessman with an interest in alchemy, appears to have discovered phosphorus around 1669. Brand left 50 buckets of pee alone till they putrified and "produced worms." He then reduced the urine to a paste and burned it with sand to extract elemental phosphorus first from combination. Oxygen and fluorine are the two elements that have more protons per atom than phosphorus.
Therefore, oxygen and fluorine are the two elements that have more protons per atom than phosphorus.
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5. What is a chemical equation? What are the essentials of a chemical equation? What information is conveyed by a chemical equation? What are its limitations and how are they removed?
Answer:
A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and formula. (i) It must refer to an actual chemical reaction. (ii) It should be molecular. For example, H, O, N should be written as H2, O2, N2. (iii) It should be balanced and conform to the law of conservation of matter.A chemical equation conveys both qualitative and quantitative information. Qualitatively, a chemical equation tells the names of the various reactants and the products.
(01.07 HC)
A student collected the data shown in the table below during an experiment.
Liquid Characteristics
Liquid Characteristics
Boiling Point Freezing Point Color Expansion per Degree Change in Temperature
Mercury 357 °C −39 °C shiny silver gray relatively lower
Alcohol 78 °C −115 °C colorless relatively higher
Based on the data, which of the following conclusions can be made about the use of mercury and alcohol thermometers?
A mercury thermometer can measure the freezing point of a liquid that freezes at −80 °C.
An alcohol thermometer can measure the boiling point of a liquid that boils at 80 °C.
A mercury thermometer is better to measure very small changes in temperature.
An alcohol thermometer is better to measure the boiling points of colorless liquids.
Answer: a mercury thermometer is better to measure very small changes in temperature
Explanation:
i took the test and got it right
Answer:
the answer is C, a mercury thermometer is better to measure very small changes in temperature.
Explanation:
i just took the test and it was correct :)
PLZ HELP?! 50 points
Write the correct IUPAC name for the following compound
Answer:
2-ethly-3-5 dimethylheptam
Explanation:
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