During freezing, water molecules lose energy and do not vibrate or move around as vigorously. This allows more stable hydrogen-bonds to form between water molecules, as there is less energy to break the bonds. ... Thus water expands as it freezes, and ice floats atop water.
When water molecule freezes, the water molecules have slowed down enough that their attractions fixed them into fixed positions.
What do you mean by freezing ?The term freezing is defined as a phase transition where a liquid converted into a solid when its temperature is lowered below its freezing point.
The freezing point is the temperature at which a liquid turns solid. In the freezer, for example, water-filled ice cube trays.
Water molecules freeze in a hexagonal pattern, with molecules further apart than when the water was liquid. It is worth noting that the molecules in ice would be vibrating.
Thus, When water freezes, the water molecules slow down to the point where their attractions arrange them into fixed positions.
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equatinal by elimination melha
8n-3y = 18 and5x+6y=27
Answer:
x = 3 and y= 2
Explanation:
Given equations:
8x - 3y = 18 - ---- (I)
5x + 6y = 27 -------(II)
Solve this problem by elimination;
In the elimination method, we simply find a common term that can make one of the variables in the two equation the same. Then we either add or subtract to remove the variable.
Mulitply equation (i) by 5 to give equation III
Mulitply equation (II) by 8 to give equation IV
5(8x - 3y) = 5(18) ------- III
8(5x + 6y) = 8(27) ------- IV
40x - 15y = 90------- III
40x + 48y = 216 ------- IV
Subtract equation III and IV;
-15y - 48y = 90 - 216
- 63y = -126
y = 2
Solve for x;
40x - 15y = 90;
40x - 15(2) = 90
40x - 30 = 90
40x = 90 + 30
40x = 120
x = 3
What is the decomposition of 2LiCIO3
Which describes the elements in a given group of the periodic table?
They decrease in atomic mass as you go down the column.
They increase sequentially in atomic number from top to bottom.
They are in the same family, with similar characteristics.
Their properties change according to a pattern as you go down the column.
Answer:
They are in the same family, with similar characteristics.
Explanation:
The elements in a given group of the periodic table are in the same family and with similar characteristics.
Vertical columns on the periodic table are referred to as a group or family. Elements having the same number of electrons in the outermost shell of their atoms are placed one another in vertical columns. Each resulting vertical column is a group or family. Elements in the same group exhibit similar chemical properties because of the same number of electrons in their atoms' valence shells.How many moles are in a sample of 2.39 x 10^23 atoms of sodium (Na)
Answer:
The answer is 0.4 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{2.39 \times {10}^{23} }{6.02 \times {10}^{23} } \\ = 0.39700996...[/tex]
We have the final answer as
0.4 molesHope this helps you
During the Metric Olympics yesterday, Molly's long jump was 118.3 cm. Christy accidentally recorded her results in inches. She jumped 51.18 inches. Can you help... Who won the long jump? Christy won by about 30 cm Christy won by about 30 cm Molly won by about 25 cm Molly won by about 25 cm Christy won by about 12 cm Christy won by about 12 cm Molly won by about 10 cm
Answer: Christy won Molly by 12cm
Explanation:
Ist step
Molly's ;ong jump was 118.3cm
Christy long jump was 51.18inches
2nd Step
we change christy score to cm so we can compare
1 inch = 2.54cm.
therefore 51.18 inches = 51.18 x 2.54= 129.9972cm
Christy won molly by 129.9971cm-118.3cm=11.69 rounded to 12cm
Christy won Molly by 12cm
Volcanic belts form along
a.
islands in the Pacific Ocean.
b.
North American mountain ranges.
c.
the boundaries of Earth’s plates.
d.
the coast of Antarctica.
Please select the best answer from the choices provided
Please i need to pass this!
Please try
It is incorrect because it should have a total of eight electrons with two electrons between each H and O
Further explanationLewis structure shows the form of bonds that occur in the valence electrons of an element or compound
This bonding usually occurs in covalent bonds
Valence electrons are electrons used in a chemical bond
The main group elements usually have valence electron configurations in the ns and np subshells, While the transition elements in the subshells (n-1) d and ns.
Element O has 6 valence electrons
Element H has 1 valence electron
To achieve stability, the element O needs 2 more electrons which are obtained from 2 electrons from the H element, while the H element needs 1 electron to be stable
So that a covalent bond is formed
What occurs to the particles in a fluid during convection ?
Answer: what are options
Explanation:
Calculate the volume 3.00 moles of a gas will occupy at 24.0 °C and 762.4 mm Hg.
Answer:
Use formula of PV = nRT
Change formula to solve for Volume = nRT/P
R is a constant 0.08206
Convert C to Kelvin which is just +273
And turn mmHg into atm which is around 1 atm
Plug in and solve
Do you guys have viruses wit this website
What causes the air above a pot of boiling water to become warm?
The air transfers thermal energy to the water vapor.
The water vapor transfers thermal energy to the air.
The particles in the air lose kinetic energy.
The particles in the water vapor gain kinetic energy.
Answer: The water vapor transfers thermal energy to the air.
Explanation:
You have a solution of water and pure ethanol. The boiling point of water is 100 degrees Celsius and the boiling point of pure ethanol is 78 degrees Celsius. A. What process would you would use to separate this solution? Describe, in detail, how this process works.
Answer:
Distillation
Explanation:
A solution of water and ethanol are miscible. Hence, they can only be separated by a process known as distillation. Distillation is the process in which two or more constituents in a mixture are separated based on there difference in boiling points. The mixture is subjected to high heat and the one with the least boiling point distills/evaporates out first followed by the next least boiling point.
From the explanation above, it can be deduced that ethanol (with boiling point of 78°) will be distilled out while water remains in the boiling tube or container.
Why are biopharmaceuticals in high demand?
Answer:
the market is largely driven by the growing population, increasing burden of chronic disease, and rising inclination toward targeted therapy.
Explanation:
also, the huge demand of biopharmaceutical is facilitated by an accelerating focus in research and related investment.
What is the mass of 0.250 mol of chlorotrifluoromethane, CCIF3?
A. 26.1 g
B. 104 g
C. 4.78 x 10-3 g
D. 52.2g
Answer:
26.1g
Explanation:
Cclf3
=35.5
F=54/101.5
Mass=mol*mm
=0.25*1015
=26.1g
In reality, energy conversion from burning fuel is never 100% efficient. Significant loss of energy due to heating occurs. If the generator were only 20% efficient (which is more realistic), how much energy in joules would be converted to electrical energy and how much would be lost to heat? (2 points)
Answer:
Electrical energy = 130000000 J and Heat energy = 520000000 J
Explanation:
Multiply the amount of joules from the last question (650000000) by .20 and .80. (Which are the percentages)
Calculate the heat that must be supplied to
a 532 , stainless steel vessel containing 375 g
of water to raise its temperature from 35 C
to the boiling point of water 100°C. Cs. =0.51 J/g. degrees C
Answer in units of J.
Q must be supplied = 119523.3~J
Further explanationThe law of conservation of energy can be applied to heat changes, i.e. the heat received/absorbed is the same as the heat released
Q in = Q out
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
So from the question :
Q to the system(Q supplied) = Q water + Q steel vessel(Q gained)
[tex]\tt Q~supplied=m.c\Delta T(water)+m.c\Delta T(vessel)\\\\Q~supplied=375\times 4.18\times (100-35)+532\times 0.51(100-35)\\\\Q~supplied=101887.5+17635.8=119523.3~J[/tex]
Whas the the ionic radius of strontium
Answer: 255 pm
Explanation: Hope this helps!
You are conducting an experiment with two very reactive substances. One will react with oxygen (O) and other substances in the air, and the other will react to metal in a container. What type of environment can you seal them in so they only react with each other?
Answer:
seal them in a glass container in an atmosphere of argon (Ar) gas
Explanation:
Scientists and nutritionists have long suspected that high-fructose corn syrup, used to
sweeten soft drinks, is one of the causes of childhood obesity. In a recent study, at the
University of Cincinnati, researchers found that mice that drank water with added
fructose ate less solid food, gained more weight, and put on 90% more body fat than
mice that drank only water. Scientists concluded that fructose may affect metabolism in
a way that favors fat storage.
What is the independent variable?
The mice that drank only water
The presence of fructose in their diet
The quantity of water provided
The weight gained by the mice
Answer:
The presence of fructose in their diet
Explanation:
The independent variable in an experiment is the type of variable which is changed at intervals in order to study if it has a direct effect on the dependent variable.
The dependent variable in the experiment is the amount of weight gained by the mice in each group and the control group is the mice who drank the water without the fructose added.
Neturally an atom is neutral in charge why
Answer
Explanation:
an atom is usually define as a perfect balance of electrons and protons
2. Calculate the density of a rock that has a mass of 21.58 grams and causes the water in a
graduated cylinder to rise from 20.0yl to 25.4 ml.
Answer:
4.00 g/mL
Explanation:
Density is mass divided by volume (g/mL).
Mass of rock = 21.58
Volume of rock = 25.4 - 20.0 = 5.4mL
Density of rock = 21.58g / 5.4mL = 3.99629 g/mL
Round to the lowest number of significant figures which is three = 4.00 g/mL
Explain three ways the periodic table is organized. Include in your essay the
definition of two listed trends and the patterns observed for each of your selected
trends on the periodic table
Answer:
The periodic table is organized in non-metals metals and metalloids, in in terms of trends and patterns you may want to talk about the the density of the elements or the mass of per unit of measurement of whatever you're going to use sorry that could be much help but I hope it helps.
Which refers to a method that relies on sound waves and is used by different animal species for navigation,
communication, and finding food?
echolocation
analog signaling
infrared detection
o digital location
HELP FAST ILL MARK BRAINLEST
Answer:
A
Explanation:
got it on edge
An echolocation refers to a method that relies on sound waves and is used by different animal species for navigation, communication, and finding food. Therefore, option A is correct.
What is an echolocation ?Echolocation is a method used by bats, dolphins, and other animals to locate objects using reflected sound. This enables the animals to move around in complete darkness, allowing them to navigate, hunt, recognize friends and enemies, and avoid obstacles.
(1) To hunt for prey, bats make high-frequency sounds. (2) Sound waves are used by dolphins and other toothed whales to locate prey and navigate their surroundings. (3) Nocturnal oil birds use echolocation to navigate their surroundings, particularly in low-light conditions.
Echolocation is used to help with orientation, obstacle avoidance, food acquisition, and social interactions.
Thus, option A is correct.
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Help ASAP!!!! Plz!!!!!!!
choose the letter that best describes the behavior of a substance during a phase change:
/A/ neither absorbs or releases energy
/B/ always absorbs energy
/C/ always releases energy
/D/ either absorbs or releases energy
Answer:
/D/ either absorbs or releases energy
Explanation:
During a phase change energy is either absorbed or released.
A phase change is a reversible process which occurs when a substance changes is its state from one form to another.
Phase changes are used to delineate physical changes.
A phase diagram provides a graphic representation of the change. The diagram can be 2 dimensional or 3 dimensional.ANSWER ASAP PLEASE!!
What determines how many of each ion is required for an ionic compounds?
please do not look up on google!!!!
Each ion has a single charge, one positive and one negative, so we need only one ion of each to balance the overall charge. When writing the ionic formula, we follow two additional conventions: (1) write the formula for the cation first and the formula for the anion next, but (2) do not write the charges on the ions.
32 N of Force. 37 N force. How strong is the net force and in which direction?
If the density of a substance is 2.18 g/mL, how would you find the density given that the mass is 0.987 kg and the volume is 4.52 x 102 mL?
Answer:
Explanation:
Convert mass in gms .. 987 gms
Density = mass/ volume
= 987/4.52 x102
= 2.18 g/mL
Please can I have help on question e as I’m really stuck.I promise I’ll give out brainiest
The relative atomic mass of element A : 6.075 u
Further explanationThe elements in nature have several types of isotopes
Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
Mass atom X = mass isotope 1 . % + mass isotope 2.% ...
Element A
mass number of isotope 1 = 6 , percent : 92.5%
mass number of isotope 2 = 7, percent : 7.5
Relative atomic mass of element A
[tex]\tt = 92.5\%\times 6+7.5\%\times 7\\\\=5.55+0.525=6.075~u[/tex]
Is a backpack a good resource
for a rescue team?