The element in the seventh group and the third period will have 7 energy Levels and a valence of 3. The element in 7th group and 3rd period is cobalt (Z = 27).
What is groups in periodic table?Groups in periodic table are vertical columns with elements having same number of valence electrons and similar chemical and physical properties. The valence of an element is the number of electrons that have to gained gained or lost from the element to achieve octet.
The element in 7th group and third period is cobalt with the atomic number of 27. The number of valence electrons is 9 in which 2 are in s electrons and 7 are in d orbital.
Therefore Co needs 3 more electrons to attain complete electronic configuration in d -orbital. Hence, there are 7 energy levels and valence of 3 for Co.
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(12) Magnesium metal burns very brightly to produce heat and a white solid.
What type of chemical reaction is taking place?
An endothermic
B exothermic
C reduction
D thermal decomposition
Answer:
exothermic
Explanation:
heat/energy is released when it burns.
why is conventional solar electricity is so expensive to generate??
Answer:
Most solar cells are made from silicon—the same semiconductor material that is at the heart of computers. The cells are expensive to produce because it takes a great deal of energy to purify the silicon.
Help me pretty please
The pressure in a Red Rider BB gun cartridge is 1.5 atm. If the rifle was at 25 °C prior to firing, what is the temperature change of the cartridge after firing if the cartridge reaches standard air pressure of 1.0 atm?
Answer:
–99 °C
Explanation:
From the question given above, the following data were obtained:
Initial pressure (P₁) = 1.5 atm
Initial temperature (T₁) = 25 °C
Final pressure (P₂) = 1 atm
Change in temperature (ΔT) =?
Next, we shall determine the final temperature. This can be obtained as follow:
Initial pressure (P₁) = 1.5 atm
Initial temperature (T₁) = 25 °C + 273 = 298 K
Final pressure (P₂) = 1 atm
Final temperature (T₂) =?
P₁/T₁ = P₂/T₂
1.5 / 298 = 1 / T₂
Cross multiply
1.5 × T₂ = 298
Divide both side by 1.5
T₂ = 298 / 1.5
T₂ = 199 K
Converting 199 K to °C, we have:
T(°C) = T(K) – 273
T₂ = 199 – 173
T₂ = –74 °C
Finally, we shall determine change in temperature. This can be obtained:
Initial temperature (T₁) = 25 °C
Final temperature (T₂) = –74 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = –74 – 25
ΔT = –99 °C
Thus, the change in the temperature is –99 °C
Convert 160g to mg.
Answer:
160 grams is equal to 160,000 milligrams.
Explanation:
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Hope it helps!
Answer:
1g=1000mg
160g=160000
PLEASE Answer! Using the periodic table, predict the order of decreasing electronegativity for the elements Al, Ag, Ca, Se, and I.
AL is aluminum, last, that stuff blows up in microwaves 5
Ag is silver, 3
Ca is calsium 2
Se is a metaloid, Selenium, 4
I is Iodine- first 1
Help pleaseee :( .....
Answer:
A
Explanation:
Plate Tectonics Independent Practice,
Label The Diagram With The Correct Information.
Answer:
1st Diagram (at the left) → Mid-Atlantic Ridge
2nd Diagram (at the right) → Andes Mountains
3rd Diagram (below) → San Andreas Fault
Explanation:
I have been able to label the diagram with the correct information.
The 1st diagram at the left is the Mid-Atlantic Ridge. This is a divergent plate boundary that is found at the floor of the Atlantic Ocean. It is also seen as part of the mountain range in the world. The Mid-Atlantic Ridge also includes a deep rift valley. This rift valley runs along the axis of the ridge. This is along nearly its entire length.
The Andes Mountains is found along the Pacific Ring of Fire. It is seen in a Mesozoic–Tertiary orogenic belt of mountains. The Andes rises due to the compression of the western rim of the South American Plate. It is a result of tectonic plate processes.
San Andreas Fault is known to form the tectonic boundary which exists between the Pacific Plate and the North American Plate. The motion of the fault is right-lateral strike-slip. It divides into three segments.
Help me pretty please
Answer:
Light demonstrates wave-like and particle-like characteristics
Explanation:
Light itself is a wave but under circumstance it will present particle-like charcteristics. This is called wave-particle duality :)
explain what is meant by an exothermic reaction and write balanced equation for any two exothermic changes
Please do not answer from links
Please answer correctly
Urgent
[tex] \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \red{ \underline{ \large \orange{\tt{ ꧁ A \: N\: S \: W \: E \: R ꧂}}}}[/tex]
✧ [tex] \large{ \red{\tt{E\:X \: O \: T \: H \: E \: R \: M \: I \: C \: \: R \: E \: A \: C \: T\: I \: O \: N}} : }[/tex]
☃ The chemical reaction in which heat is released to the surroundings is called exothermic reaction. The amount of heat energy released is written along with products. This indicates that heat is given out.
[tex] \pink{ \text{Any \: two \: balanced \: equation \: for \: Exothermic \: changes}} : [/tex]
C + O₂ ⇾ CO₂ + HeatCaO + H₂O ⇾ Ca ( OH )₂ + Heatツ Hope I helped! ♡
☂ Have a wonderful day / night ! ☄
[tex] \underbrace{ \overbrace{ \mathfrak{Carry \: On \: Learning}}}[/tex] ✎
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For the reaction So3 + H2O -> H2SO4, how many grams of sulfur trioxide are required to produce 4.00 mol of sulfuric acid
Answer:
320 grams of sulfur trioxide are required to produce 4.00 mol of sulfuric acid.
Explanation:
The balanced reaction is:
SO₃ + H₂O → H₂SO₄
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
SO₃: 1 moleH₂O: 1 moleH₂SO₄: 1 moleBeing the molar mass of each compound:
SO₃: 80 g/moleH₂O: 18 g/moleH₂SO₄: 98 g/moleBy reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
SO₃: 1 mole* 80 g/mole= 80 gramsH₂O: 1 mole* 18 g/mole= 18 gramsH₂SO₄: 1 mole* 98 g/mole= 98 gramsThen you can apply the following rule of three: if 1 mole of sulfuric acid is produced by the reaction of 80 grams of sulfur trioxide, 4 moles of sulfuric acid is produced from how much mass of sulfur trioxide?
[tex]mass of sulfur trioxide= \frac{4 moles of sulfuric acid* 80 grams of sulfur trioxide}{1 mole of sulfuric acid }[/tex]
mass of sulfur trioxide= 320 grams
320 grams of sulfur trioxide are required to produce 4.00 mol of sulfuric acid.
The mass of the required compound is 320 grams
Chemical reactionsGiven the chemical equation expressed as:
[tex]SO_3 + H_2O \rightarrow H_2SO_4[/tex]
According to stochiometry, 1 mole of SO3 produces 1 mole of H2SO4, hence the moles of SO3 will also be 4.00moles
Determine the mass of SO3
Mass = mole * molar mass
Mass = 4.0 * [32+3(16)]
Mass = 4.0 * 80
Mass = 320 grams
The mass of the required compound is 320 grams
Learn more on stoichiometry here: https://brainly.com/question/16060223
Krupton (Kr) is a
A. Gas
B. Metal
C. Non of these
D. Metalloid
Answer: C. None of these
Explanation: Krypton is a noble gas, on the right side of the period table, making it a non-metal.
Calculate the pOH and the pH of a 5.0 x 10-2 M solution of NaOH.
Answer:
pOH = 1.3, pH = 12.7
Explanation:
Since NaOH is a strong base, it will completely ionize; further, since it completely ionizes, our hydroxide concentration (a product of the ionization) will be the same as the given concentration of NaOH.
NaOH -> Na⁺ + OH⁻, [OH⁻] = 5.0 x 10^-2 M
pOH is the negative log of the hydroxide concentration, so plug our hydroxide concentration in:
pOH = -log[OH⁻] = -log[5.0 x 10^-2 M] = 1.3
Since pH + pOH = 14, we can plug in pOH and solve for pH:
pH + 1.3 = 14
pH = 14 - 1.3 = 12.7
Thus, our pOH = 1.3 and pH = 12.7.
what is a characteristic of a strong acid
Answer:
Strong acids have mostly ions in solution, therefore the bonds holding H and A together must be weak. Strong acids easily break apart into ions. Weak acids exist mostly as molecules with only a few ions in solution, therefore the bonds holding H and A together must be strong
Answer:
Bond Strength
Explanation:
Strong acids have mostly ions in solution, therefore the bonds holding H and A together must be weak. Strong acids easily break apart into ions. Weak acids exist mostly as molecules with only a few ions in solution, therefore the bonds holding H and A together must be strong.Aug 15, 2020
The spreading of a mechanical wave into the region behind an obstruction is called --------- what ?
Diffraction occurs whenever a portion of a wavefront is obstructed by some opaque object.
I’m sorry I’m confused can you help me?
Answer:
2 electrons
Explanation:
The first principal energy level contains only an s sublevel; therefore, it can hold a maximum of two electrons.
Most large mountains are the result of a(n)?
River
Volcano
Earthquake
Hurricane
Answer:
C.) Earthquake
Explanation:
Most mountains occur due to the movement of tectonic plates. They slowly push into each other, and the earth's crust rises over time forming mountains.
Earthquakes occur due to the shift of tectonic plates. It sends seismic waves throughout the earth's crust, and causes the ground to shake temporarily.
Look at the wave in the picture. If it has a wavelength of 2 cm, how far apart are points A and B? How do you know?
Answer:
picture is not there.....
Explain why, if soil on a vehicle is in a clump, care
should be taken to keep the clump intact.
Answer:
it could harbor dangerous chemicals that damage the car if released
it could be holding parts together
it could have something dangerous inside
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3. Connect to Technology How do probes,
including landers and rovers, improve our
ability to make observations of other planets?
s
balance : _ Na + _ H2O
Answer:
2, 2
Explanation
Need help plssss!!!!!
Answer:
a
Explanation:
becsaus
A student suggests that the colorless liquid collected in the U‐tube is water.
Describe how to test the colorless liquid to show it contains water.
Answer:
How would you confirm that a colourless liquid given to you is pure water? A very easy solution is to take a sample of the colourless liquid and put it on the stove if it starts boiling exactly at 100 ºC then it is pure water. Any other colourless liquid such as vinegar always has a different boiling point.
Help me pretty please
Answer:
The top answer
Biologist group living things based on ____. Habitat Habitat Size Size Colors Colors Shared Characteristics
Answer: i think it is Habitat but i am not 100%
Explanation:
What is the ratio of the number of molecules in 1 L of CO2(g) to the number of molecules in 1 L of CH4(g) at the same temperature and pressure? * 2 points 1:1 3:5 1:2 2:4
Answer:
1:1
Explanation:
Based on Avogadro's law, the volume of an ideal gas is directly proportional to the moles (Or number of molecules) presents of this gas under constant temperature.
The volume of the gas is independent to the nature of the gas
Using this law, we can change the state as:
X number of molecules of CO₂ in X number of molecules of CH₄ (Because are occupying the same volume). That means the ratio of molecules is:
1:1which of the following describes the properties of a substance?
A. how it reacts with other chemicals.
B. how it behaves.
C. all of these.
D. how it looks
4. Write word equations of
Magnesium burns in chlorine to form Magnesium Chloride
Answer:
Mg(s) + Cl₂ -------> MgCl₂
Explanation:
If yeast is given more sugar will they undergo more
cellular respiration than yeast that is given less sugar?
Answer:
True
Explanation:
Cellular respiration is a metabolic pathway that allows cells to take apart food molecules and use their atoms as an energy source. This pathway takes electrons from food molecules and transfers them to oxygen, has energy transferred to ATP and arranges molecules into water, carbon dioxide and waste.
A single atom is in a balanced electrical state.
It has the same number of which pair of particle types?
electrons and neutrons
protons and electrons
neutrons and isotopes
protons and neutrons