How many kilograms of the rock must be processed to obtain 2.0 kg of Pb ?
A sample contains 430 mg of mercury. How many significant figures are in the number?
In the unit cell of galena, six square faces of equal size each form 90 degree angles with every adjacent face. What type of crystal system is this
Your teacher gives you a black powder. When you dissolve the powder in water, you see red particles that float to the top, black particles that sink to the bottom, and a green liquid. Was the black powder a pure substance, mixture, element, or compound? compound element pure substance mixture I think it is A
Answer: Option (a) is the correct answer.
Explanation:
A substance that cannot be broken down into simpler substances is known as an element.
For example, a piece of sodium metal contains only atoms of sodium.
Whereas a compound is defined as a substance that contains two different elements which are chemically combined together in a fixed ratio by mass.
For example, LiCl is a compound in which atoms are present in 1:1 ratio.
A compound is able to dissociate into its constituent particles but an element cannot.
Both an element and a compound are pure substances.
A mixture is defined as a substance in which two or more number of different substances are mixed together. Particles of a mixture never combine chemically to each other.
So, when black powder on coming in contact with water dissociates as red particles that float to the top, black particles that sink to the bottom, and a green liquid. Then it means a chemical reaction has taken place.
Hence, we can conclude that the black powder is a compound.
In the game of economics, goods are objects that fulfill peoples needs and ____.
Goods are objects that fulfill peoples needs and wants.
compare and contrast sometimes you use your senses to make observations to find the answer to a question. Other times you use tools and measurements to provide answers. Compare and contrast these two methods of answering scientific questions.
When this element was discovered, it exhibited luster and malleability, and it reacted very vigorously with water. This element is never found as a free element in nature and always exists in a compound. To which group does this element most likely belong?
The element likely belongs to Group 1: The Alkali Metals, which are characterized by their luster, malleability, and vigorous reaction with water. They are never found free in nature and always exist in compounds.
The element described is likely to belong to Group 1: The Alkali Metals. These elements exhibit luster and malleability, and they react vigorously with water, typically forming alkaline solutions. They are never found as free elements in nature due to their high reactivity, particularly with water and oxygen in the air, and are always found in compound form.
Alkali metals include lithium, sodium, potassium, rubidium, cesium, and francium, each having a single electron in their outermost shell, which is very easily removed during chemical reactions making them very reactive.
How many moles are in 110 grams of NaHCO3?
Final answer:
There are approximately 1.31 moles of NaHCO3 in 110 grams of the compound. This is calculated by determining the molar mass of NaHCO3 and then dividing the mass by the molar mass.
Explanation:
To calculate the number of moles in 110 grams of NaHCO₃ (sodium bicarbonate), we need to follow these steps:
First, we determine the molar mass of NaHCO₃ by adding the atomic masses of its constituent elements: Na (sodium), H (hydrogen), C (carbon), and O (oxygen).Therefore, there are approximately 1.31 moles of NaHCO₃ in 110 grams of the compound.
the correct formula for aluminum phosphide
Which of the following is a scientific question?
Why do leaves change color?
What time will the next earthquake happen?
What is the best flavor of ice cream?
Where is the fountain of youth?
Which part of the atom has to stay the same for it to be the same element? a) number of neutrons b) number of protons c) number of electrons d) number of protons, neutrons, and electrons
how might a scientist confirm the result of other experiments by doing an experiment?
Answer:
The correct answer will be- repetition of the experiment ensures the validity and truthfulness of the results.
Explanation:
In the scientific community, the repetition of the experiment using the same procedure by the same researcher or another researcher plays an important role.
The repetition of the experiment is done to test and verify the results which could be doubtful or fraud. The experimental results of another experimenter act as evidence which if similar supports the experiment and help ensure the validity of the experiment.
Thus, the repetition of the experiment ensures the validity and truthfulness of the results is the correct answer.
4. What does the data mean for people involved in farming and agriculture?
Answer:
There are several benefits farmers and owners of agribusinesses.
It is often said that one cannot manage what they can't measure. Data helps farmers manage with better efficiency their operations. They can make more tailored decisions with respect to their farm’s specific needs if they have more information.When data is obtained and analysed, it generates information. The information obtained can help farmers identify efficiencies that lead to higher productivity and profitability, lower input costs, and optimise use of important farm input such as fertiliser and feed.Data help farmers reduce the risks associated with their operations. One of such risks is Market risks. If a farmer has adequate information about how a particular product is performing in the market with respect to demand and trends, it helps them plan production in such a way that they don't over produce thus creating a surge in supply which can lower prices. This is also beneficial to a farms supply chain relationships or network.Cheers!
The graph represents the heating of water in a pot. At 150 seconds, the water has just reached a boil. If the heat is left on, what will happen to the temperature and volume of water in the pot? (All temperatures in °C.) Temperature graph A. The temperature will rise, and the water volume will decrease. B. The temperature will rise, and the water volume will remain constant. C. The temperature will remain constant, and the water volume will decrease. D. The temperature will remain constant, and the water volume will remain constant.
Answer:
c
Explanation:
What is the difference between Boron (B) and Neon (Ne).
( Please answer correctly and not asking me to look on google)
the density of gold is 19.3 g/cm^3. You inherit a gold bar that measures 7.0 in by 3.0 in by 2.0 in. How many ounces does the bar weigh? Express answer in scientific notation.
To find the weight of the gold bar, we need to calculate its volume and use the density of gold. The gold bar weighs approximately 467.96 ounces.
Explanation:To find the weight of the gold bar in ounces, we first need to calculate its volume in cubic inches and then convert it to cubic centimeters.
Given:
Length = 7.0 inchesWidth = 3.0 inchesHeight = 2.0 inchesThe volume (V) of a rectangular prism is given by V = Length x Width x Height.
V = 7.0 in x 3.0 in x 2.0 in = 42.0 in³
Since 1 inch is equal to 2.54 centimeters, we can convert the volume to cubic centimeters:
V = 42.0 in³ x (2.54 cm/in)³ = 686.98 cm³
Now, to find the weight of the gold bar in ounces, we can use the density of gold, which is 19.3 g/cm³.
The formula for density is Density = Mass/Volume.
Since we know the density and the volume, we can rearrange the formula to solve for the mass:
Mass = Density x Volume
Mass = 19.3 g/cm³ x 686.98 cm³ = 13,257.814 g
Finally, to convert the mass from grams to ounces, we divide by 28.35 grams/ounce:
Weight in ounces = 13,257.814 g / 28.35 g/oz = 467.96 oz
Therefore, the gold bar weighs approximately 467.96 ounces.
The tip of a match is ignited as it is struck against the matchbox. Why is this a chemical change?
The color of the match tip has changed.
The match changes size as it burns.
The tip of the match is flammable and is set on fire.
The match is melting.
This is a chemical change as the products have very different property as compared to reactant not only physically but also chemically. Therefore option c is correct option
What is chemical change?
Chemical change is a reaction in which breaking and forming of new bonds take place. One molecule completely converted to totally different molecule. The number of atoms remains same
One famous example of chemical change is the rusting of iron. In our case tip of match is ignited as it is struck against the matchbox, so here combustion reaction is taking place, Red phosphorous is burning in presence of oxygen. The color, odor and arrangements of atoms in products are very much different from reactant.
Therefore, the tip of the match is flammable and is set on fire is the correct one . The correct option is option C
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An atom with an atomic number of 12 and a mass number of 25 can best be described by which of these?A) An atom that contains 12 protons and 13 neutrons. B) An atom that contains 13 protons and 12 neutrons. C) An atom that contains 12 protons and 25 neutrons. D) An atom that contains 25 protons and 12 neutrons.
Answer: The correct answer is Option A.
Explanation:
An atom consists of 3 subatomic particles: Electrons, neutrons and protons.
Atomic number is equal to the number of electrons or number of protons.
Atomic number = Number of electrons = Number of protons ....(1)
Mass number is the sum of number of protons and number of neutrons.
Mass number = Number of protons + Number of neutrons .....(2)
We are given:
Atomic number = 12
Mass number = 25
From equation 1:
Number of protons = Number of electrons = 12
From equation 2:
Number of neutrons = 25 - 12 = 13
Thus, an atom contains 12 protons and 13 neutrons.
Hence, the correct answer is Option A.
During an oil spill, oil coats the surface of the water, endangering sea life. Why doesn’t oil dissolve in ocean water
In two or more complete sentences, explain how to balance the combustion equation: ___C5H12 + ___O2 ⟶ ___CO2 + ___H2O
PLEASE HELPPPPP!!!!
Answer: [tex]C_5H_{12}+8O_2\rightarrow 5CO_2+6H_2O]/tex]
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Combustion is a type of chemical reaction in which fuel is reacted with oxygen to form carbon dioxide and water.
[tex]C_5H_{12}+O_2\rightarrow CO_2+H_2O]/tex]
The balanced equation will be :
[tex]C_5H_{12}+8O_2\rightarrow 5CO_2+6H_2O]/tex]
science question down below
What is the function of a hypothesis in the scientific inquiry process?
students calculated the circumference of a globe to be 60.0 cm. The actual circumference of the glide is 63 cm. The percent deviation of the students calculation was. 1. 0.48% 2. 2.8% 3. 5.0% 4. 21%
Answer: The correct answer is Option 2.
Explanation:
To calculate the percentage error, we use the equation:
[tex]\%\text{ error}=\frac{|\text{Experimental value - Actual value}|}{\text{Actual value}}\times 100[/tex]
We are given:
Experimental value of circumference = 60.0 cm
Actual value of circumference = 63 cm
Putting values in above equation, we get:
[tex]\%\text{ error}=\frac{|60.0-63|}{63}\times 100\\\\\%\text{ error}=4.8\%[/tex]
Hence, the correct answer is Option 2.
The andromeda galaxy is located approximate 2.5 million light-years from earth. Why is the light that Reaches earth 2.5 million years old
Explain why it is important that there be no gaps around the edges of the filter paper
during a vacuum filtration.
Vacuum filtration is a separation technique that is used to separate a solid product from a liquid. The method involves pouring the mixture of the solid and the liquid through a filter paper that is inserted inside a funnel. The filter paper trap the solid while the liquid is drawn through the funnel into the flask by a vacuum. It is very important to ensure that there is no gap around the edges of filter paper that is inserted into the funnel so that the mixture will not escape the filter paper and be poured directly into the flask below, thus messing up the separation process.
if you mix together 50 mL of a strong acid and 50 mL of a strong base what would yo predict the pH of the new solution wouod be
If you mix together 50 mL of a strong acid and 50 mL of a strong base what would yo predict the pH of the new solution would be 7. Because it neutralized the solution.
What is pH ?The pH scale, which previously stood for "potential of hydrogen," is used to describe how acidic or basic an aqueous solution is. The pH values of acidic solutions are lower than those of basic or alkaline solutions.
At 25 °C, the pH of pure water (H20) is 7, but when this equilibrium is subjected to atmospheric carbon dioxide, the pH of the water decreases to about 5.2 because the airborne CO2 dissolves in the water and produces carbonic acid.
Thus, If you mix together 50 mL of a strong acid and 50 mL of a strong base what would yo predict the pH of the new solution would be 7. Because it neutralized the solution.
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five years ago, my grandfather was five times as old as I was. Three years from now, my grandfather will be three times as old as I will be. how old am I now?
You should know the location of safety equipment
in the laboratory and
1. use or test it once a month.
2. where it is produced.
3. use or test it once a week.
4. how to use it properly
What is the group number of the most nonmetallic group that contains metalloids? What is the group number of the most metallic group that contains metalloids?
What is the group number of the most nonmetallic group that contains metalloids?
16
What is the group number of the most metallic group that contains metalloids?
13
Explanation:
Metalloids are the substances which show properties of both metals and non-metals.
The left side of periodic table contains metals and on moving towards the right there are non-metals. Between the metals and non-metals there are metalloids.
Group 16 is the most non-metallic group that contains metalloids. In group 16, O, S, and Se are non-metals whereas Te and Po are metalloids.
Group 13 is the most metallic group that contains metalloids. In group 13, Al, Ga, In and Tl are all metals whereas boron is a metalloid.
Which element had the longest effect on human history?