Heating a substance causes molecules to speed up and spread slightly further apart, occupying a larger volume that results in a decrease in density. Cooling a substance causes molecules to slow down and get slightly closer together, occupying a smaller volume that results in an increase in density.
From: www.middleschoolchemistry.com
Who wants to do my acellus work? Or know how to get the answers ?
im just answering questions to get points Explanation:
i dont know what points do
Answer:
Hello I passed my Chemistry exam (Acellus) in the beginning of June:)
Explanation:
What is the mass in grams, if you have 8.42 x 10^18 atoms of Bromine
Answer:
84.2 grams
Explanation:
you have to multiply 8.42x10^18 to get the answer above
The number of the atom can be used to estimate the mass and moles of the substance by Avogadro's number. The mass of 8.42 x 10¹⁸ atoms of Bromine is equivalent to 0.0011 grams.
What is the mole concept?The mole concept has been the unit of the amount of estimating the mass of the substances with smaller entities. It uses the SI unit mol to measure the amount of mass. It also has been defined by 6.02214076 × 10²³ (Nₐ, Avogadro's number) elementary entities.
The molar mass of Bromine (Br) is 79.904 u and atoms are 8.42 x 10¹⁸.
Atoms to mass are converted as:
= ( 8.42 x 10¹⁸ atom ÷ 1 ) × ( 1 mole Br ÷ 6.02214076×10²³ ) × (79.904 gm Br ÷ 1 mol Br)
= (8.42 x 10¹⁸ × 79.904 gm) ÷ 6.02214076 × 10²³
= 6.727 × 10²⁰ ÷ 6.02214076 × 10²³
= 1.117 × 10⁻³ grams
Therefore, 0.0011 grams is the mass of bromine.
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How did Mendeleev decide which elements should be placed in the same group of the periodic table?
Answer:
He grouped elements with similar chemical and physical properties.
Hope this helps
Is there a relationship between density of an object and whether it will float sink or water in water?
Answer:
yes there is...........
Answer dis please I will like and 5 star if correct
i need help to pass my class
Answer:
B
Explanation:
The attraction is stronger when the magnet is closer so moving it away would decrease the strength.
Which of these substances is a mixture?
a: none of these are mixtures
b:Lemonade
c: gold
d: sugar
Answer:
Lemonade
Explanation:
Its a mixture of stuff to make a sweat drink :D
What is a possible reason that ecosystem 2 has fewer species than ecosystem 1?
it doesn't repopulate as fast because ecosystem 2 could have more trouble reproducing then ecosystem 1.
Prompt
Explain how plate tectonics have changed Earth's surface over time. Include the role of plate tectonics in the creation of landforms.
Answer: The theory of plate tectonics tells us that the earth's surface sits on plates that shift due to the built up pressure underneath. When the pressure gets too much, it has to escape somewhere so it goes to the edges of the plate and causes earthquakes. This in turn causes the surface to shift.
What has the higher first ionization energy? Mg or Cl
Ionization Trend: First ionization energy will increase left to right across a period and increase bottom to top of a family (column).
If we compare Mg and Cl:
Mg is column 2 (far left) in the periodic table, while Cl is column 17 (far right). Based on the ionization rule explained above, Cl will have the higher first ionization energy.
how does tungsten most common isotope relate to the average atomic mass of the element
Answer:
It has the most quantitative effect on the average atomic mass of the element.
Explanation:
Tungsten's most common isotope will have the most quantitative effect on the average atomic mass.
The most common isotope of tungsten will represent its most abundant isotope.
The proportion by which each element occurs in nature is the geonormal abundance. The geonormal abundance is used to calculate the average atomic mass.The isotope with the most geonormal abundance will have the highest effect on the average atomic mass of an element.
Characteristics help scientists ______objects.
(A) isolate
(B) identify
(C) theorize
(D) quantify
Answer:
b
Explanation:
identify objects.
How many significant figures are in 20600?
There are 3 significant figures in 20600.
Which is NOT a source of bias? Pick one.
A. Accurate Records
B. Equipment Choice
C. Funding Source
D. Hypothesis Information
Answer:
A: Accurate Records
Explanation:
What is the Mechanical advantage of a machine that only changes the direction of the force?
Answer: 1
Explanation:
The number of times a machine increases a force exerted on it The input force will be the same as the output force.
What is the atomic number, icon, mass of potassium?
This should be EASY!
Answer:
19, K, 39.098
Explanation:
Potassium is a chemical element with symbol K and atomic number 19.
Atomic Mass: 39.098u
The atomic weight of iodine is less than the atomic weight of tellurium. However, Mendeleev listed iodine after tellurium in his original periodic table because he suspected the atomic weights for these elements were inaccurate. What was Mendeleev's reason for this suspicion?
Explanation :
As we know that Mendeleev arranged the elements in horizontal rows and vertical columns of a table in order of their increasing relative atomic weights.
He placed the elements with similar nature in the same group.
According to the question, the atomic weight of iodine is less than the atomic weight of tellurium. So according to this, iodine should be placed before tellurium in Mendeleev's tables. But Mendeleev placed iodine after tellurium in his original periodic table.
However, iodine has similar chemical properties to chlorine and bromine. So, in order to make iodine queue up with chlorine and bromine in his periodic table, Mendeleev exchanged the positions of iodine and tellurium.
As we know that the positions of iodine and tellurium were reversed in Mendeleev's table because iodine has one naturally occurring isotope that is iodine-127 and tellurium isotopes are tellurium-128 and tellurium-130.
Due to high relative abundance of tellurium isotopes gives tellurium the greater relative atomic mass.
Can someone help me find the 5 digits numbers in here?
Answer:
20322
Explanation:
If carbon lost one proton, what atom would be formed
Answer:
boron
Explanation:
boron has 5 protons and carbon has 6, so if carbon lost a proton, it would become boron since each element has a unique number of protons.
As each element has a different number of protons, boron has five and carbon has six, so if carbon lost one of its protons, it would change into boron.
What is proton ?Every atom has a proton, a subatomic particle, in its nucleus. The particle possesses an electrical charge that is positive and opposite to the electron's.
In the reaction, a proton is forfeited. Keep in mind that when the number of protons changes, the atomic number also changes, creating a new element. Carbon-14 is the end result as a result. It is a new element, yet it has the same mass as nitrogen-14.
When carbon creates covalent bonds, pairs of electrons are shared between the atoms instead of being gained or lost as happens with chemical bonds. The ability of carbon to construct lengthy chains of atoms and so create intricate biological compounds is due in part to this feature.
Thus, If carbon lost one proton, boron atom would be formed.
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The change of matter, solid, liquid and gas is called a_________.
Answer:
This would be a phase change
Explanation:
Since the diffrent phases solid,liquid,gas are changing to other phases.
Sorry for the bad explanation.
pls help me i have to turn this in in less than 15 min.
Answer:
Last one
Explanation:
Answer:
Boiling point!
Explanation:
Distilled water is capable of being heated beyond the normal boiling point due to absence of dissolved impurities which provide nucleating points at the normal boiling point.
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How many grams of sugar must be dissolved in 150 mL of water to make a solution with a concentration of 0.6 g/mL?
Answer:
250
Explanation:
all you have to do is divide them its simple division cause its by the volume by the density
Mass can be calculated by using moles which can be further calculated from multiplication of Molarity to volume. The mass of sugar to make this solution is 8.6 kg.
What is molarity?
Molarity can be calculated by dividing number of moles of solute by volume of solution in litre. Molarity is affected by temperature. Its unit is mole/litre. It measure the concentration of any solute in a solution.
Other concentration terms are molality, normality and mole fraction. Molarity can be used to find out the ionic strength of any solution
Mathematically,
Molarity= number of moles of solute/volume of solution in litre
Where,
moles= given weight /by molecular weight
= w/ 96.0858
Substituting values in equation 1
0.6=(w/96.0858)/(150 )
w=8.6 kg
Thus the mass of sugar is 8.6 kg.
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how did rutherford contribute to atomic theory?
Explanation:
Rutherford’s laboratory showed that when alpha particles are fired into gas atoms, a few are violently deflected, which implies a dense, positively charged central region containing most of the atomic mass.
If the molar mass of a hydrocarbon is 26.0 g/mol and it’s empirical formula is CH what is the molecular formula
Which is a characteristic of calcium?
A.It has two neutrons
B.It has two energy shells
C.It has two protons
D.It has two electrons in its outer energy shell
Explain why energy sources do not have 100% efficiency. Why do you think some have lower efficiencies?
Answer:
Energy sources do not have 100% efficiency because the processes of energy conversion to usable forms involves energy losses.
Some have lower efficiencies due to; energy losses in form of heat during conversion, poor technology applied during conversion of energy and lack of desire equipment to use in the energy conversion system.
Explanation:
The desired form of energy for use is derived from conversion of energy from the source using an energy converter into another form which is usable. The efficiency of the energy converter is calculated as;
л = output energy/input energy
The efficiency of energy is limited to the cost of equipment required for conversion from energy source by the energy converter to a form which is usable. Additionally, because energy sources are scarce, the technology to use in energy conversion is a factor affecting energy efficiency in that high efficiency will require advanced technology with better equipment leading higher costs of that energy form. when heat losses are involved during energy conversion, efficiency lowers, thus its better if such losses are used as energy input in another system.
Explain what is meant by the natural abundance of isotopes. Can someone help me to answer this plz
How do you know which elements increases or which elements decreases on a Ionisation graph? Like how can you figure out that these elements will increase on the graph and which will decrease?
Explanation:
There is a trend in the periodic table.
I.E increases up the group and across the period. So you know that metals have less I.E compared to non-metals.
I NEED HELP QUICK Activity:
Part 1: Write all bold vocabulary and define the words (See attached PDF File below). Make sure to number each.
Part 2: Look at the "Second Read of Investigating Landforms On Venus" worksheet (Slide 14) and highlight text to the questions on the worksheet.
Part 3: Answer the questions on the "Second Read of Investigating Landforms On Venus" worksheet: 1) How were the novae on Venus similar to the landforms in Geyra's computer model? AND 2) How did the results of Gerya's model provide evidence for what formed the novae on Venus? (Slide 16)
Part 4: Write the notes: (Slide 19)
3) Scientists can use models to test their ideas and get evidence about processes in the natural world that are difficult to observe.
Exit Slip: How do models help scientists answer questions?
I don't understand how and why some transition metals form more than one ions eg: copper forms two. PLS EXPLAIN. I WILL GIVE YOU BRAINLIEST.PLS EXPLAIN PROPERLY AND IN FULL DETAIL. I AM IN YEAR 9.
THANKYOU
USE COPPER OXIDE IONS AS AN EXAMPLE.
7-8 POINTS
Answer:because some have more radiation than others causing mutations and there for either decreasing or increasing the amount of ions
copper is a acidic metal in general therefor it will most likely erode faster than any other metal making it hard to determan the number of ions in general the metal will have basicly what I’m trying to say is there is no solid answer as many metals can change there ions for no given reason
Explanation: