Answer:
all calcium atoms have an atomic number of 20 but there are three isotopes of calcium - 39, 40, and 42
What are the transitional elements?
Answer:
Transitional element are those elements which partially fill D and F subsells.
Answer:
an element having a d subshell that is partially filled with electrons, or an element that has the ability to form stable cations with an incompletely filled d orbital
What is the volume of sodium hydroxide,
NaOH solution used to neutralised 25.00 mL
of 0.1500 M hydrocloric acid, HCI?
Answer:
sorry i don't know this question answeer
trong chuẩn độ, dung dịch có nồng độ chưa biết là định nghĩa của?
Answer:
skip it please, ok...? thank you
What is the mass of the silver sphere in kg?
Mixture of oil and water heterogeneous?give reasons.
Answer:
because mixed particles are visible in this mixture.
Answer:
Oil and water do not mix, instead forming two distinct layer called phase. The oil phase is less dense than the water phase, and so the oil floats on top of the water.
help me plz this is import this thing is late and comfusing i can give you vrainliest
Answer:
can you please mark me brainliest pleaseSome insects, like bees, can see light of shorter wavelengths than humans can see. What kind of radiation do you think a bee sees?
Answer:
ultraviolet light (UV light)
'How many atoms are in 2.45 moles of copper?
2.46 × 1023 atoms
2.45 atoms
155.70 atoms
1.48 × 1024 atoms
Answer:
[tex]\boxed {\boxed {\sf 1.48 \times 10^{24} \ atoms \ Cu}}[/tex]
Explanation:
We are asked to find how many atoms are in 2.45 moles of copper (Cu).
We can convert moles to atoms using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of copper. There are 6.022 × 10²³ atoms of copper in 1 mole of copper.
We will convert using dimensional analysis, so we must set up a ratio using Avogadro's Number.
[tex]\frac {6.022 \times 10^{23}\ atoms \ Cu}{ 1 \ mol \ Cu}[/tex]
We are converting 2.45 moles of copper to atoms, so we multiply the ratio by this value.
[tex]2.45 \ mol \ Cu*\frac {6.022 \times 10^{23}\ atoms \ Cu}{ 1 \ mol \ Cu}[/tex]
The units of moles of copper cancel.
[tex]2.45*\frac {6.022 \times 10^{23}\ atoms \ Cu}{ 1}[/tex]
The denominator of 1 is the same as the numerator by itself, so it can be ignored.
[tex]2.45* {6.022 \times 10^{23}\ atoms \ Cu}[/tex]
[tex]1.47539 \times 10^{24} \ atoms \ Cu[/tex]
The original measurement of moles (2.45) has 3 significant figures, so our answer must have the same. For the number we found that is the hundredth place. The 5 in the thousandth place to the right tells us to round the 7 up to an 8.
[tex]1.48 \times 10^{24} \ atoms \ Cu[/tex]
There are approximately 1.48 × 10²⁴ atoms of copper in 1 mole of copper.
Answer:
[tex]:\implies \rm Moles =\dfrac{No. \: of \: atoms}{Avogadro's \: number} \\ [/tex]
[tex]:\implies \rm M =\dfrac{N}{N_A} \\ [/tex]
[tex]:\implies \rm N=M \times N_A \\ [/tex]
[tex]:\implies \rm N=2.45\times6.022 \times {10}^{23} \\[/tex]
[tex]:\implies \rm N=14.7539\times {10}^{23} \\[/tex]
[tex]:\implies \rm N=1.47539\times 10^1\times {10}^{23} \\[/tex]
[tex]:\implies\textsf{ \textbf{N = 1.48$\times${10}$^{24}$}} \\[/tex]
What is the mass of 5 mole of ammonia . Calculate the number of NH₃ molecules, nitrogen atom and hydrogen atoms in it..
Molar mass of NH_3
[tex]\\ \sf\longmapsto 14u+3(1u)[/tex]
[tex]\\ \sf\longmapsto 14u+3u[/tex]
[tex]\\ \sf\longmapsto 17g/mol[/tex]
We know.
No of moles=Given mass/Molar mass
[tex]\\ \sf\longmapsto Given\;Mass=17(5)[/tex]
[tex]\\ \sf\longmapsto Given \:Mass\:of\:NH_3=85g[/tex]
Now
Lets write the balanced equation
[tex]\\ \sf\longmapsto N_2+3H_2=2NH_3[/tex]
There is 2moles of Ammonia 3moles of H_21mole of N_2Now
[tex]\boxed{\sf No\:of\:Molecules =No\:of\;moles\times Avagadro\:no}[/tex]
For Hydrogen
[tex]\\ \sf\longmapsto 3\times 6.023\times 10^{23}[/tex]
[tex]\\ \sf\longmapsto 18.069\times 10^{23}[/tex]
[tex]\\ \sf\longmapsto 1.8\times 10^{22}molecules[/tex]
For Ammonia
[tex]\\ \sf\longmapsto 2\times 6.023\times 10^{23}[/tex]
[tex]\\ \sf\longmapsto 12.046\times 10^{23}[/tex]
[tex]\\ \sf\longmapsto 1.2\times 10^{22}molecules[/tex]
For Nitrogen
[tex]\\ \sf\longmapsto 1\times 6.023\times 10^{23}[/tex]
[tex]\\ \sf\longmapsto 6.023\times 10^{23}molecules[/tex]
temperature at which the substance changes from solid to liquid is known as the:
Answer:
it is called the melting point
Which of the following are considered elements:
Answer:
considered as element
Helium He
Move the following term into the correct category
mixture
pure substance
Possible answers:
compound
air
salt in water
H2O
soda
element
Answer:
Explanation:
*Mixture this is the mixing of two or more substances by physical means.
*Pure substance are substance that can not be spotted by ordinary physical means.
*Compound are substance that combine by chemical means.
* Air is are mixture of gass with different percentage..they have no general molecular formula.
* This is the ability for a salty compound to ionize in water.
* Formula for water.
* Compound containing sodium , carbon and oxygen.
*This are pure substance that can not be spited by ordinary chemical means.
3. What is the best explanation for the decrease in first ionization energy moving from Be to B?
(A) Moving from Be to B, more electrons are added to the
atoms, thus increasing the electron-electron repulsions.
(B) Moving from Be to B, more protons in the nucleus
attract the valence electrons, making it harder to remove
the electrons.
(C) The electrons in Be are being removed from a full sub- shell, which is more stable than the half-filled sub-shell in B.
(D) The electrons in Be are located in the 2s subshell. These electrons penetrate closer to the nucleus than the 2p electrons in B.
Answer:
The electrons in Be are located in the 2s subshell .These electrons penetrate closer to the Nucleus than the 2p electrons in B
Explanation:
See the Electronic Configurations
[tex]\\ \sf\longmapsto Be=1s^22s^2[/tex]
[tex]\\ \sf\longmapsto B=1s^22s^22p^1[/tex]
2s orbitals are more powerful than 2p orbitals.The best explanation for the decrease in first ionization energy moving from Be to B is option d. The electrons in Be are located in the 2s subshell.
The Explanation for reducing the first ionization energy:When there is reduction in the first ionization energy that moved from be to B so here the electrons in Be should be located in the 2s subsell.
Also, these electrons should penetrate closer to the nucleus as compared to the 2p electrons in B.
Hence, the option d is correct.
learn more about ionization here: https://brainly.com/question/18648019
Need answer for 9.0mm x 2.0mm x 2.0mm
Answer: 36
Explanation: good luck
The answer for 9.0mm x 2.0mm x 2.0mm is 36 mm³ or 0.036 milliliters.
What is Conversion factor ?A conversion factor is a number used to change one set of units to another, by multiplying or dividing.
When a conversion is necessary, the appropriate conversion factor to an equal value must be used.
Volume fo object = Side³
= 9.0mm x 2.0mm x 2.0mm
= 36 mm³
Therefore, The answer for 9.0mm x 2.0mm x 2.0mm is 36 mm³ or 0.036 milliliters.
Learn more about volume here ;
https://brainly.com/question/1578538
#SPJ2
If the average speed of a helium atom at a certain temperature is 1110 m/s, what is the speed in miles per hour? (1 mi = 1609 m)
please help and show how its done
Answer: 2483 miles/hour
Explanation:
[(1 mile/1609 meters) = 0.0006215 miles/meter]
(1110meters/sec)*(0.0006215 miles/meter)*(3600 secs/hour) = 2483 miles/hour!
Note how the units cancel to yield miles/hour. Use the units to determine what conversion factors are needed. We know that the final unit was to be miles/hour, so we converted meters into miles (firsy line) so that the meters would cancel, leaving only miles. Same for seconds and hour (3600 secs/hour).
Archer is a soil scientist and needs to examine a bacteria sample. He wants to be able to change his magnification with different objective lenses. Which microscope should he choose?
A. Compound light microscope
B. Transmission electron microscope
C. Dissecting microscope
D. Scanning electron microscope
Answer:
C. Dissecting microscope
Explanation:
It is trying to see the surface
True or False?Proteins are an important nutrient because they provide the elements nitrogen and sulfur, which are not provided by dietary carbohydrates and lipids.
conversion from 76 pounds to 1 gram
Answer:
76 Pounds = 34,473,020 Grams
Answer:
76 Pounds = 34,473,020 Grams
Explanation:
becuase one pound weighs 453.592 grams so i just added up
How are thermal energy, particle motion, and temperature related?
Thermal energy of a substance is obtained by absorbing temperature. Thermal energy is increased by the particle motion where an increase in kinetic energy is followed by an increase in thermal energy.
What is thermal energy?Thermal energy is a form of energy gained by the absorption of temperature and results in thermal expansion of particles. As the temperature increases, the particles gains sufficient energy to move apart.
Thus, kinetic energy of molecules increases by thermal expansion. Thereby volume of the system increases. Kinetic energy is the energy generated by virtue of the motion of particles in an object.
According to kinetic theory of gases kinetic energy of particles increases with an increase in thermal energy and vice versa.
Therefore, it can be said that the thermal expansion of particles is caused by the kinetic energy gained by them which is acquired by the thermal energy gained by the particles through the absorption of temperature.
To find more on thermal energy, refer here:
https://brainly.com/question/11278589
#SPJ6
The gas laws explain how __ gases ___ . There is actually no such thing as an ideal gas, but these laws still explain generally how gases behave. The separate laws combine into an “_____”.
what’s the missing blanks ?
The gas laws explain how ideal gases are . There is actually no such thing as an ideal gas, but these laws still explain generally how gases behave. The separate laws combine into an equation ”.
Hope it helps you...
Answered by Benjemin
What is the correct way to smell a chemical
Answer:
If you need to smell the odor of a chemical, waft or fan the fumes toward your nose with one hand. Do not put your nose over the container and inhale the fumes.
What will form when we add Co2 plus H20.
help me please. i wil mark you brainlist.
if your answer helps me i will add your name and tells other to follow you
Answer:
CO² + H²O ---------). H²CO³answer is this. all the numbers above alphabet will be bellow. while writing remember
Explanation:
CO² mean Carbon dioxide
H2O mean Water
H²CO³ mean Carbonic acid
Carbon dioxide+H²O = Carbonic acid
mark me brainlist if it helps
Boys diagram for sulfur
Answer:
here is a diagram of Bohr's sulfur.
When you wash your hands or dishes, you probably don't use just water. In 5-7 sentences, explain what
you use to help you wash up, how it works, and why you think it works.
Hello! here is a paragraph you can use, that I type up to explain, make sure to not copy word for word of what I said. :)
What I use to wash up is soap. Soap has a certain ph level and includes acids and alkaline that enables water to mix and create soap foam to clean. Soap can come in many shapes and sizes, and can be either liquid, solid, or even foamy. I think soap works because when you use friction between your wet hands and the soap bar, you are rubbing the substances of the soap that clean your hands to clean your hands. I think the friction of the rubbing creates a layer of soap that can be used to clean, and when you increase friction the more change of the soap.
Have a great day,
I hope this helps!
Of the following, which compound has the highest boiling point? Hexanone Hexanoic acid 1-Hexanol Hexanal
electrons are the most
important electrons to an atom. a) outer b) inner
Identify the contents of the following mixtures. Select all that apply. Each circle is an atom. Different colors are used for different types of atoms. Indicate atoms only for atoms not bound to other atoms. Please remember that the elemental form of some materials is simply the atom itself.
Answer:
What’s the question
Explanation:
The distance of 24 km equals:
O 2.4x104 m
O 2.4x10-1 m
O 2.4x103 m
2.4x10-2 m
2.4x102 m
Answer:
2.4* 10⁴ m
Explanation:
1km = 1000m = 10³m
(1*24)km = 10³ * 24 m
=> 24km = 2.4 * 10⁴m
A patient is required to take an IV drug for cancer treatment. The required dosage is 5.0 mg drug her lb patient body weight every day. Each of the bags of the drug contains 250 mg drug. If you are treating a 150 lb patient,How many bags of the drug are needed each day.
Answer:
3 bags are required.
Explanation:
Find the number of mg needed for 150 pounds
150 pounds * 5 mg/pound = 750 mg
1 bag = 250 mg
x bags = 750 mg Cross multiply
250 * x= 750 Divide by 250
x = 750/250
x = 3
Which of the following is NOT a chemical?
O sound
sugar
9
water
12
salt
Answer:
water is not the chemical hope ur help
