The question is incomplete, the complete question is;
The table above summarizes data given to a student to evaluate the type of change that took place when substance X was mixed with water. The student claimed that the data did not provide enough evidence to determine whether a chemical or physical change took place and that additional tests were needed. Which of the following identifies the best way to gather evidence to support the type of change that occurred when water and Xwere mixed?
A. Measuring the melting point of the mixture of water and X
B. Adding another substance to the mixture of water and X to see whether a solid forms
C Measuring and comparing the masses of the water, X, and the mixture of water and X
D Measuring the electrical conductivities of X and the mixture of water and X
Answer:
D Measuring the electrical conductivities of X and the mixture of water and X
Explanation:
Unfortunately, I am unable to reproduce the table here. However, from the table, the temperature of the of the mixture of the solid X and water was 101.6°C. This is above the boiling point of water and way below the temperature of the solid X.
This goes a long way to suggest that there was some kind of interaction between the water and X which accounted for the observed temperature of the system of X in water.
The only way we can be able to confirm if X actually dissolved in water is to measure the conductivity of the water. dissolved solids increase the conductivity of water.
The statement which identifies the best way to gather evidence to support the type of change that occurred when water and X were mixed is:
D Measuring the electrical conductivities of X and the mixture of water and XAccording to the given question, we are asked to show the statement which identifies the best way to gather evidence to support the type of change that occurred when water and X were mixed. \
As a result of this, we can see that from the complete question, there is a need to note the temperature of the solution which is 101.6°C and then to measure the conductivity of the water to know for sure the type of change that occured.
Therefore, the correct answer is option D
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Use your answers from questions 1–3 as the basis for the first section of your lab report. This section provides your reader with background information about why you conducted this experiment and how it was completed. Outline the steps of the procedure in full sentences. It also provides potential answers (your hypothesis/es) relative to what you expected the experiment to demonstrate. This section should be 1–3 paragraphs in length.
Answer:
1-state what the lab is about, that is, what scientific concept (theory, principle, procedure, etc.) you are supposed to be learning about by doing the lab. You should do this briefly, in a sentence or two. If you are having trouble writing the opening sentence of the report, you can try something like: "This laboratory experiment focuses on X…"; "This lab is designed to help students learn about, observe, or investigate, X…." Or begin with a definition of the scientific concept: "X is a theory that…." 2-give the necessary background for the scientific concept by telling what you know about it (the main references you can use are the lab manual, the textbook, lecture notes, and other sources recommended by the lab manual or lab instructor; in more advanced labs you may also be expected to cite the findings of previous scientific studies related to the lab). In relatively simple labs you can do this in a paragraph following the initial statement of the learning context. But in more complex labs, the background may require more paragraphs.
Explanation:
Answer: the correct answer is A
Explanation:
Chemistry, please help
Answer:
Name ; Nickel(ii)Hydroxide
Formula;NI3O6
Explanation:
A wave with a small wavelength has a high frequency.
options:
True
False
Calculate the number of moles of Na+ ions in 25g of sodium carbonate?
Explanation:
First, we need to calculate the number of moles of sodium carbonate we have in a 25 g sample. To calculate this, we will
find the molar mass of sodium carbonate (Na2CO3):
⇒ 2 × Molar mass of sodium + Molar mass of carbon + 3×molar mass of oxygen
⇒ 2 × 23 + 12 + 3 × 16
⇒ 46 + 12 + 48
⇒ 106g/mol
Thus, the molar mass of Na2CO3 is 106g/mol.
Therefore, number of moles = 25 ÷ 106
=> 0.2358 mol
Now, we know that every mole of Na2CO3 have 0.2358 moles of Na+ ions. Hence, total moles of Na2CO3 is 0.4716 moles
Number of ions present = 6.022 × 1023 × 0.4716 mol = 2.84 × 1023ions
The molar mass of sodium carbonate is 106 g/mol. One mole of sodium carbonate gives 2 Na+ ions. Thus number of moles in 25 g of sodium carbonate is 0.47 moles.
What is sodium ions?Sodium ion Na+ is formed by the lose of one electron from the sodium metal. Sodium has one valence electron and it will reacts with other atoms by donating this electron and gaining a positive charge.
The molecular formula of sodium carbonate is Na₂CO₃. Therefore, one mole of sodium carbonate will give two moles of Na+ ions. The molar mass of sodium carbonate is 106 g/mol.
The number of moles of 25 g of sodium carbonate is calculated as follows:
Number of moles = 25 /106
= 0.235 moles.
It is clear that one mole of Na₂CO₃ gives two moles of sodium ions.Then, number of moles of sodium ions given by 0.235 moles of sodium carbonate is calculated as follows:
number of moles of Na+ = 0.235 × 2
= 0.47 moles
Hence, the number of moles of Na+ ions produced by 25g of sodium carbonate is 0.47 moles.
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Question: How hot is the sun?
Answer:
5,778 K
Explanation:
What is a non-example of a nucleus? Please give me a non-living thing.
Answer:
They are prokaryotes and both have tough cell walls. ◦ The cytoplasm contains ribosomes, but no organelles. ◦ There is no nucleus for organisms in this category.
Explanation:
Answer:
rock- non living
( Prokaryotes don't have a nucleus)
Explanation:
Which statement correctly describes a characteristic that a scientific measurement tool should have
Answer:
to be procice, it must use small units to take mesurements
Explanation:
a.pex
Q 1. Element M is a metal that forms compounds of the type MX2, MX3, and MX4, where X is a Chlorine (Cl).
I) What is the expected trend in the ionic radius of M in these compounds?
II) Arrange these compounds in order of decreasing ionic radius of M.
Do not respond if u don’t know the answer. I’ll report it and u will get a warning.
Answer:
See explanation
Explanation:
The ionic radius of metal M decreases as the magnitude of charge on the metal M increases. The ionic radius is the distance between the nucleus and the electron in the outermost shell of an ion. So, ionic radius decreases with increasing positive charge.
We can see that from the various formulae in the question that the metal forms cations M^2+, M^3+ and M^4+ respectively. The order of decreasing ionic radius of the compounds is;
MX2 > MX3 > MX4
Answer:
dont know
Explanation:
What is the name of the group that contains potassium?
O Noble Gases
O Halogens
O Alkaline Earth Metals
O Alkali Metals
Transition Metals
Answer:
Alkali Metals
Explanation:
Meg used two examples to represent two different states of matter.
Example 1: Young children dancing slowly around one another
Example 2: Newborn babies sitting in their given spots in a crib
Which statement is correct? (1 point)
a
Example 1 represents a gas and Example 2 represents a liquid.
b
Example 1 represents a liquid and Example 2 represents a gas.
c
Example 1 represents a liquid and Example 2 represents a solid.
d
Example 1 represents a solid and Example 2 represents a liquid.
Answer:
c Example 1 represents a liquid and Example 2 represents a solid.
Explanation:
Example 1: Young children dancing slowly around one another
The young children dancing slowly around one another can be pictured as the flow of liquid. In liquids, the molecules are held about weakly and they slide on top of each other. They are held by weak attractive forces. This is clear picture of a liquid.
Example 2: Newborn babies sitting in their given spots in a crib
This is clear example of a solid. In a solid the molecules are held about a fixed spot. The attractive forces in liquids is very great and the molecules therein do not move about randomly.
Match the term (exothermic) with the correct definition.
energy goes into the chemical and cool downs the surrounding area.
energy leaves the chemical and cools down the surrounding area
energy leaves the chemical and heats up the surrounding area
Answer:
energy leaves the chemical and heats up the surrounding area
Explanation:
which of the following metals are more reactive than mercury? Select all that apply
a. silver
b. iron
c. lithium
d. potassium
What are the alkaline earth metals?
A. Group 2 elements
O B. Group 18 elements
C. The transition metals
D.
up 1 elements
What is the volume of a 25 g object with a density of 9.1 g/mL? please help me
Answer:
The answer is 2.75 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question we have
[tex]volume = \frac{25}{9.1} \\ = 2.747252...[/tex]
We have the final answer as
2.75 mLHope this helps you
With over 6 billion people living on Earth, it is common for two people to have the same DNA.
True
ОR
False
How many atoms of nitrogen are in the chemical formula Ni(NO3)2?
Answer:
2
Explanation:
bc the 2 that's after a bracket refers to both oxygen and nitrogen, making oxygen 6 bc it already has a 3(3×2=6)
Answer:
2
Explanation:
Which statement describes a positive effect of selective breeding? A. Some desirable traits in a population can disappear. B. Offspring can be prone to genetic diseases. C. Parents can pass on useful traits to offspring, D. A population can end up with a lack of genetic diversity .
Answer:
C. Parents can pass on useful traits to offspring
Explanation:
Answer:
The Answer is C
Explanation:
explain why the reaction between lead (II) nitrate and concentrated sulphuric (VI) acid starts and stops immediately?
Answer:
The reaction produces insoluble lead (II) sulphate which coats the surface of lead (II) nitrate [Pb(NO3)]
Under a certain set of conditions, the percent yield of a reaction that produces carbon dioxide is 75.0%. What mass in grams of CO2 will actually be recovered if the theoretical yield is 26.7 grams?
Answer:
Actual yield = 20.03g
Explanation:
[tex]% yield = 100.\frac{actual yield}{theoretical yield}[/tex]% [tex]yield[/tex] = [tex]100. \frac{actual \ yield}{theoretical \ yield}[/tex]
Actual yield = % yield.(theoretical yield) / 100
Actual yield = 75.26.7/100
Actual yield = 20.025
Answer: I got 20.025 and then I rounded it to 20.0
Explanation:
Which subatomic particles are found in the nucleus of an oxygen atom?
F Neutrons and Electrons
G Electrons and Protons
H Protons and Neutrons
J Protons, Neutrons, and Electrons
Answer:
the answer is protons and neutrons
Explanation:because
The subatomic particles are found in the nucleus of an oxygen atom are Protons and Neutrons. Thus, option H is correct.
What are subatomic particles?An electron is defined as a subatomic particle which is charged negatively either bound to an atom or not it means free. The nucleus of an atom is made up of electron, proton and neutron. The electron is a basic particle and electron is not made of anything.
The nature of electron is free it means they are present freely in nature and consist of an atom.The main function of electron is that they play the role of negatively- charged component of an atom.
The electrons are primary source of current conducting and electrons number as well as atomic number of an element is always same or equal. There is no size of electron but the mass of electron is 9×10^-31.
Therefore,The subatomic particles are found in the nucleus of an oxygen atom are Protons and Neutrons. Thus, option H is correct.
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1. H2SO4, sulfuric acid, contains three different types of atoms: hydrogen (H), sulfur (S), and oxygen (O). Each of these atoms represents a different . Since the three types are combined in a fixed ratio, this means that H2SO4 is a(n) molecule. 2. The smallest unit of matter that retain all of the physical properties of that type of matter is a(n) atom. 3. is anything that occupies space and/or has any substance. 4. If two or more atoms are bonded together, they form a(n) . 5. The scientific study of matter is called . 6. Within a plant, water (H2O) and carbon dioxide (CO2) can be combined (using the energy of sunlight) to produce glucose (C6H12O6) and oxygen (O2). If you were to write out this chemical reaction, water and carbon dioxide are each an example of a(n) while glucose and
Answer:
The blanks can be completed with words in the following sequence
1) elements
compound
2) atom
3) matter
4) compound
5) chemistry
6) reactants
product
Explanation:
In H2SO4, atoms of hydrogen, sulphur and oxygen represent different elements that are combined to form the compound.
The smallest indivisible unit of matter that still retains all the properties of matter is an atom. Matter is anything that has weight and occupy space.
Atoms combine in fixed ratios to form compounds. Chemistry studies matter scientifically and pays specific attention to the changes that matter undergoes.
Considering the reaction of photosynthesis, water and carbon dioxide combine to give glucose so the water and carbon dioxide are reactants while the glucose is the product of the reaction.
The volume of an object is 55mL in this city is 30g/mL. what is its mass
Answer:
Mass = 1650g
Explanation:
30g per mL is the density I suppose...
Solve for m!
30g/mL = m/55mL
Multiply by denominator to get numerator!
30* 55 =1650g
m = 1650g
Brainliest Appreciated!
A compound is made of two or more different atoms joined together. which image would best fit
Answer:
Where is your images?
Explanation:
cant solve the prblm without ur images
What percentage of Carbon (C) is present in one molecule of
Dichlorodifluoromethane (CF2Cl2), commonly known as Freon, an anti-freezing agent
used in automobiles.
Please round everything to whole numbers for this question. Use the following
masses in your calculations:
C = 12
F = 19
Cl = 35
The percentage of Carbon (C) present in one molecule of
Dichlorodifluoromethane (CF₂Cl₂) : 10%
Further explanationProust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements
With this law, we can calculate how many grams an element is needed to make a compound with a certain mass, as desired
MW Dichlorodifluoromethane (CF₂Cl₂) :
=12+2.19+2.35=120 g/mol
[tex]\tt \%mass~C=\dfrac{12}{120}\times 100\%=10\%[/tex]
show how acid and base given below dissociates in water
Answer:
HOME is acid
KOH is base
if a star were 36 trillion miles from the earth it would be about ___ light years from the earth
Answer:
6.12light years
Explanation:
Given parameters:
Distance of star from earth = 36 trillion miles
Unknown:
Distance in light years = ?
Solution:
A light year is the distance light travels in one year.
1 mile = 1.7 x 10⁻¹³ light years
36 trillion miles = 36 x 10¹² x 1.7 x 10⁻¹³ light years
= 6.12light years
Which of these ions has the correct charge?
O2-
B2+
P2-
Li2+
Answer:
02- i think your welcome hope it helps
which bond is the strongest
Answer:
C
Explanation:
When two atoms share electrons, a covalent bond is formed. The more electrons shared between atoms, the stronger the bond. Single bonds have two electrons shared, double bonds have four electrons shared, and triple bonds have six electrons shared.
Therefore, triple bonds are the strongest as they require more energy to break.
Hope that helps.
Where does cellular respiration occur?
A.in your stomach
B. in your lungs
C.in your circulatory system
D.in your cells
Someone help me please i’ll give brainly
Answer:
Gas, liquid, and plasma
Explanation:
Answer:
Liquid, Gas and Plasma
Explanation:
➨Think about it like this if you put a material made out of these and flipped it over which one would have the most effect of change in shape?
▶Liquid molecules slide past each other meaning they are not held in place.
▶Gas molecules are "excited" they bounce around everywhere meaning they are not held in place.
▶Plasma has no fixed shape or volume so it cant be held in place!
▶Solid molecules have a fixed shape so they cannot move on their own.
Hope I helped! Brainliest appreciated!