Answer:
Which
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A pan containing 20.0 grams of water was allowed to cool from a temperature of 95.0 °C. If the amount of heat released is 1,200 joules, what is the approximate final temperature of the water?
75 °C
78 °C
81 °C
87 °C
Answer:
81 °C
Explanation:
This is a calorimetry question so a few things you will need for this. The calorimetry equation q=mcΔT & the specific heat of water (4.2J/g•°C). Other definitions are:
q = heat added/released by a sample
m = mass of sample
c=specific heat of sample
ΔT = change in temperature
from here we can rearrange the equation to state:
q/(mc) = ΔT
1200J/((20.0g)(4.2J/g•°C)) = ΔT
14°C = ΔT
If the starting temperature was 95.0°C and we know that the temperature was cooled by 14°C then the final temperature of the water would be 81.
Answer:
C. 81 c
Explanation:
took the test :)
Freezing water cracking limestone
a
Chemical Change
b
Physical Change
Answer:
Freezing water and cracking limestone are physical changes.
Soot is formed as a candle burns
a
Chemical Change
b
Physical Change
Answer:
Chemical change
Explanation:
Because a new substance is formed.
3. What of the following determines an atom's identity?
A. Protons
B. Neutrons
C. Electrons
D. Nucleus
Answer:
protons
Explanation:
the number of protons in a nucleus are equal to the number of atoms in an element.
Protons determines an atom's identity. Therefore, the correct option is option A among alt the options.
Three essential elements make up an atom: protons, neutrons, and electrons. The nucleus, or central portion of the atom, contains protons, which are positively charged particles. Along with protons, neutrons, which have no charge, are found in the nucleus. On the other hand, electrons are negatively charged particles that move in regions called energy levels or shells around the nucleus. An atom's atomic number and designation as an element are determined by the quantity of protons in it. The usual size of an atom is between 0.1 and 0.5 nanometers; one nanometer is equal to one billionth of a metre.
Therefore, the correct option is option A.
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giải gấp giúp em câu này với ạ:
a) Hoàn thành các phan ứng sau dưới dạng phương trình phân tử và phương trình ion thu gọn:
- CaCO3 + HCl =>
- Fe(SO4)3 + NaOH =>
- KCl + ? => KNO3 + ?
- Na2S + H2SO4 =>
b) Viết PTPU của các phương trình ion thu gọn sau, xác định chất nào là acid, chất nào là bazo:
- H(+) + OH(-) => H2O
- OH(-) + HCO3(-) => CO3(2-) + H20
Explanation:
what do you have written I can't understand one word right a properly
Which element would most likely lose electrons to form positive ions when bonding with other elements?
rubidium (Rb)
gallium (Ga)
argon (Ar)
iodine (I)
The correct answer to the question is Rubidium (Rb)
Rubidium (Rb) is a group 1 element and as such, it can form bond by losing it's valence electron (i.e 1 electron) easily.
Gallium (Ga) is a group 13 element. It can only form bond by losing it's 3 valence electrons.
Argon is a group 18 element. This group has completely filled outermost shell and are very stable. They do not involve in bond formation.
Iodine (I) is a group 17 element. It is more difficult for this group to lose its 7 valence electrons hence, they form bond by accepting 1 electron.
With the above information, we can conclude that Rubidium will most likely lose electron to form bond.
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Answer:
(Question 1)Which element would most likely lose electrons to form positive ions when bonding with other elements?
(Answer) rubidium (Rb)
(Question 2) Which statement about sodium chloride is correct?
(Answer) The sodium atom transfers electrons to the chlorine atoms to form ionic bonds.
(Question 3) Based on their locations in the periodic table, which two elements are most likely to form covalent bonds with each other?
(Answer) nitrogen (N) and oxygen (O)
(Question 4) Which phrase best describes electronegativity?
(Answer) the relative strength with which an element attracts electrons in a chemical bond
(Question 5) Based on the information in the table, which pair of elements would likely form the least polar bonds with each other?
(Answer) bromine and nitrogen
Explanation:
just finished the quick check enjoy UwU
How would you change the type of atom
Answer:
Hi, There! :)
If you change the number of protons an atom has, you change the type of element it is. If you change the number of neutrons an atom has, you make an isotope of that element.
Answer:
If you change the number of protons an atom has, you change the type of element it is. If you change the number of neutrons an atom has, you make an isotope of that element. All known elements are arranged on a chart called the Periodic Table of Elements.
Explanation:
that's what I found buddy
To reduce the costs of extracting aluminum, what must be added to it to reduce the melting point? A. Bauxite B. Cryolite C. Cathode D. Anode
Answer:
cryolite
Explanation:
B B B B B
cryolite is the answer
plss help :(((
What volume is indicated on each of the graduated cylinders below? The unit of volume is mL. Make sure to check the units of graduation to get the most accurate reading possible
Answer:
Explanation: The total volume (rock plus water) in the graduated cylinder is 34 mL. We know the volume of water in the cylinder was 20 mL. Therefore, the volume of the rock must be 14 mL. Because a milliliter is exactly the same volume as a cubic centimeter, the volume of the rock is 14 cm3.
Explanation:
Image result for The unit of volume is mL. Make sure to check the units of graduation to get the most accurate reading possible
Graduated cylinders have numbers on the side that help you determine the volume. Volume is measured in units called liters or fractions of liters called milliliters (ml).
ok guys! so! im in my first chemistry class and i dont understand what an ion is!! help please! i need a simple breakdown of how to understand chemistry
Explanation:
Review and Study Material Before Going to Class. ...
Take Good Notes. ...
Practice Daily. ...
Take Advantage of Lab Time. ...
Use Flashcards. ...
Use Study Groups. ...
Break Large Tasks Into Smaller Ones.
reading a variety of chemistry books
Answer:
An ion is an atom or molecule that carries an electric charge.
Ions are identified by the use of a superscript to show the sign and size of their electric charge.
Negatively charged ions are called anions, and positively charged ions are called cations.
Explanation:
An atom is the smallest unit of ordinary matter that forms a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small, typically around 100 picometers across.
who started water conservation in himachal pradesh
Explanation:
There are government khatris as well, which are maintained by the panchayat. Kuhls are a traditional irrigation system in Himachal Pradesh- surface channels diverting water from natural flowing streams (khuds). A typical community kuhl services six to 30 farmers, irrigating an area of about 20 ha.
Why do scientists use models of molecules?
A. To research the known effects of the molecule on the environment
B. To explain how electrons, protons, and neutrons are arranged
C. To show the structure of molecules, which are too small to see
D. To design an experimental setup to synthesize molecules
Answer:
C
Explanation:
How is bacteria are different from animals?
Answer:
Bacteria has 1 cell and An Animal has multiple cells.
Explanation:
Bacteria is a cell its self. While An Animal, It has multiple cells that create multiple tissues, and those tissues create multiple organs, those organs make up an organ system. After the Organ System, it's an organism.
Organism = Animal, Human, Ect.
Meanwhile, Bacteria is made up ONE CELL (bacteria it's self is 1 cell)
So the answer is "Bacteria has 1 cell and An Animal has multiple cells."
I hope this helped!! <33
What is the approximate mass of one electron?
Answer:
9.1093837015 × 10^−31 kg
Very small mass
An explanation for a broad of observation, facts, and tested hypothses is called a
Answer:
that's is a theory
Explanation:
hope it may help you
how to calculate valency of atoms?
Answer:
The valency of a molecule is zero.
Explanation:
Valency is calculated by calculating number of electrons present in outermost orbitals of atom of element.
Hope it is helpful.....define mass number in your own words
Answer:
The total number of protons and neutrons in the nucleus of an atom is called mass number.
Answer:
mass number also called nucleon number and it's the total number of neutron and proton in an atomic nucleus.
In the reaction 2H2 + O2 + H20, what coefficient should be placed in front of H2O to balance the reaction? 0 2 03 O 4
Answer:
2
Explanation:
2×2
2O
soooo
2H2O means 4H2O
pls
answer
pls
pls
its ma homework
Answer:
2 ka A. nitrogen, oxygen, Carbon dioxide
Answer:
no 1 Ans gas
hope it works
Label each of the following 15 samples of matter as one of the following:
WHATS THE FREEZING POINT FOR WATER
Answer:
0 degrees Celcius and 32 degrees fahrenheit
Explanation:
Which is correct?
a
Electrons in a p sublevel can shield the s electrons that are in the same
principal energy level.
b
Electrons in an s sublevel can shield the p electrons that are in the same
principal energy level.
с
Both a and b are true.
d
Neither a nor b are true.
(Physical Science)
Which group of metals includes elements with one valence electron? (1 point)
A. alkaline earth metals
B. rare earth metals
C. alkali metals
D. transition metals
Answer:
C
Explanation:
alkali metals are the Group I elements, which have 1 electron in their valence shells
Answer:
Alkali metals are the elements which have only one valence electron in their outermost or ultimate shell.
Explanation:
Alkaline Earth metals have 2 valence electron in their outermost shell and readily give up their 2 electron to achieve stability.
Rare Earth Metals have 3 valence electron in their outermost shell and they have high magnetic moments and divert range of magnetic structure.
Alkali Earth metals have 1 valence electron.
Transition metals generally have 2 valence electron .
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5
Which of the following is true regarding the particle nature of a solid?
Particles in a solid -
A
move very little, so it cannot easily change its shape.
B
are relatively far apart, so it is highly compressible.
с
are in continual motion, and can slide past each other.
D
are very far apart, so it can easily change its shape.
Answer:
this answer is b no u can it very easy
Explanation:
because solid and liquid can compress easily
plz support me
Answer:
A. move very little, so it cannot easily change its shape.
what are the three formula of mole?
[tex] \huge \boxed{\mathfrak{Formulas} \downarrow}[/tex]
For all[tex] \large \sf \: mole = \frac{mass}{molar \: mass} \\ [/tex]
For gases[tex]\large \sf \:mole = \frac{volume}{molar \: volume} \\ [/tex]
For solutions[tex]\large \sf \:concentration \: ( \frac{g}{ {dm}^{3} } ) \\\large \sf \: = \frac{mass(g)}{volume( {dm}^{3} )} [/tex]
You can substitute mass with mole for concentration (mol/dm³).If you burn a citronella candle near your picnic will it keep mosquitoes away
Answer:
Thanks!!!
Explanation:
Answer:
true
Explanation:
what happens to the food dye in hot water?
Answer:
The food coloring mixes through the hot water faster than it mixes with the cold water. The reason for this is because in hot water, the water molecules have more energy and are moving faster than the molecules of cold water. This makes it way more easier for the dye to get mixed throughout the hot water.
Explanation:
Help me,I’m so confused ..and explain pls
Answer:
1. is 50...
75/1.5 = 50
2. is 600...
300/5 is 600
3.
Part A: 45 minutes= 0.75 hours
Part B: 5.3
Explanation:
Don't agree? The calculator says other wise....
i checked it its correct.
My friend asked, Our sale is being used to measure
flour. What was the scale really measuring about
the flour?
A) color of flour
B) volume of flour
C) weight of flour
D) temperature of flour
Chemical changes can change which properties of a substance?
Group of answer choices
Reactivity
Color
Malleability
All of the above
Answer:
» Reactivity and color
Explanation:
though color is very minor answer because it also relates to a physical property.
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