Explanation:
Specific heat capacity of gold (S)
= 0.126 J /kg°C
mass (m) = 350 g = 0.35 kg
difference in temperature (dt)
= 88.5°C - 24.6°C
= 63.9° C
Now
Energy released (Q)
= m*s*dt
= 0.35 * 0.126 * 63.9
= 2.81799 Joule
Hope it will help :)
No attempt was made to test sodium with hydrochloric
acid. Why not?
Answer:
the reaction is violent and quick
Explanation:
The solubility of substance (Z) is 40g/100ml of water at 25°C. A)Can you
make a saturated solution if you add 120 g. of (Z) to 450ml of water at
25°C?
-
can anyone help me?!!!??!?!
Answer:
No, It would be a unsaturated solution
Explanation:
The solubility of a compound gives us information about how a compound may dissolve or not in a determinate solvent.
In this case we have Z, which in 25 °C the solubility of this compound is 40g/100 mL water. This means that if we have 60 g of Z and try to dissolve it in 100 mL of water, only 40 g of Z will solve and the remaining 20 g will be in the water as precipitate or remaining solid.
Now if you just put 40 g of Z in 100 mL water, it will dissolve completely in water, and in this case, we have a saturated solution. A saturated solution is when you dissolve a determinated quantity of a solute in a determinated quantity of solvent, without remaining of solid or excess of solvent.
According to this explanation, we now have 120 g of Z. To make a saturated solution of Z with this quantity, well, let's do math. If 40 g dissolves in 100 mL, then 80 g would be 200 mL and 120 g would have to be 300 mL of water. But in this case, we have 450 mL of water, we have more than 300 mL, an excess of water, so, the 120 g will dissolve but it's dissolved in more than the needed quantity to be a saturated solution, therefore, we have an unsaturated solution of Z (more solvent than the needed).
Hope this helps.
Analyze the definition of light-year. Why is it in space we use light-year to
measure distance? *
Answer:
Because the distance is too far to count with any other way
Explanation:
A chemical ____ is a force of attraction between atoms or
ions that share or transfer valence electrons.
A chemical bond is a force of attraction between atoms or ions that share or transfer valence electrons.
PLEASE HELP ME!!! I AM DESPERATE!!!
What causes infrared light to hit the ground?
Answer: The water vapor, carbon dioxide, methane, and other trace gases in the earth's atmosphere absorb the longer wavelength. These are all reasons why infrared waves hit the ground.
The water vapor, carbon dioxide, methane, and other trace gases in the earth's atmosphere absorb the longer wavelength. These are all reasons why infrared waves a part of electromagnetic spectrum hit the ground.
What is electromagnetic spectrum?The electromagnetic radiation consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.
The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.
In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.They are emitted by electrically charged particles which undergo acceleration and subsequently interact with other charged particles.
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4.Which scientist described the electrons as traveling in certain orbits or energy levels?
a.Dalton
b.Rutherford
c.Thomson
d.Bohr
5.In a famous experiment, scientists bombarded a very thin gold (Au) foil with positively charged alpha particles. They found that most of the alpha particles passed right through the Au foil. However, a few of the alpha particles were deflected or bounced back toward the source. How did these scientists explain their results?
a.Negative charges are spread throughout the atom.
b.Negative charges are located in the tiny nucleus of the atom.
c.Positive charges are located in the tiny nucleus of the atom.
d.Positive charges are spread throughout the atom.
6.The atomic mass represents the weighted average of an element’s
a.Ions
b.mass numbers
c.atomic numbers
d.isotopes
7.The number of protons is represented by the element’s
a.atomic number
b.mass number
c.atomic mass
d.isotope
8.The number of protons plus neutrons is represented by the
a.atomic number
b.mass number
c.atomic mass
d.isotope
9.How many valence electrons would an atom of Chlorine have?
a.2
b.3
c.7
d.8
10.An element is found to have 2 electrons in the 3rd energy level. What is this element?
a.Boron
b.Magnesium
c.Fluorine
d.Argon
11.Which shows the order of decreasing atomic size?
a.Si, Al, Mg, Na
b.I, Br, Cl, F
c.Be, Mg, Ca, Sr
d.C, P, Se, I
12.Which of the following elements has the highest ionization energy and why?
a.Argon because it has more protons in the nucleus.
b.Argon because it has a full valence shell.
c.Chlorine because it only needs one valence electron to fill its valence shell.
d.Chlorine because it attracts electrons better.
13.Which shows the order of increasing ionization energy?
a.Si, Al, Mg, Na
b.Ga, Ge, As, Se
c.Be, Mg, Ca, Sr
d.F, Cl, Br, I
14.Identify the reason why atoms decrease in size(atomic radius)across a period on the Periodic Table.
a.Gravity pulls the electrons in towards the nucleus.
b.Increase in energy levels increases the attraction and thus pulls electron cloud in.
c.Increasing strong positive nuclear charge from the nucleus pulls in the negative electron clouds and increases with the increase in protons and electrons.
d.Electrons lose energy and collapse with an increasing number of electrons and protons.
15.What is the shielding effect?
a.The neutrons shield protons from the attraction of the electrons from the first energy level.
b.Valence electrons are shared equally between atoms.
c.The repulsion of electrons in the same energy level.
d.The inner-core electrons shield outer-core electrons from the attraction to the atom’s nucleus.
16.Which statement is an accurate description of elements from Period 3 on the periodic table?
a.It contains elements with the same number of 3 protons.
b.It contains elements with the same number of3valence electrons.
c.It contains elements with the outermost protons in the same 3rd energy level.
d.It contains elements with the outermost electrons in the same 3rd energy level.
17.The column that an element is located in tells us
a.the total number of valence electrons an atom has.
b.the total number of energy levels an atom of that element has.
c.the highest energy level an atom of that element has.
d.both b & c.
18.The Halogen family of elements all have 7 valence electrons. Which column would they be in?
a.01 (IA)
b.02 (IIA)
c.4 (IVA) or 14
d.7 (VIIA) or 17
19.The Alkali and Alkaline Earth metals belong to which columns, respectively?
a.Column IA & IIA
b.Column VIIA & Column VIIIA
c.Column IIIA & IVA
20.What do carbon and silicon have in common?
a.They belong to the same column (family), therefore they have the same number of valence electrons.
b.They belong to the same column (family), therefore they have the same number of total electrons.
c.They belong to the same column (family), therefore they have the same number of energy levels.
d.They belong to the same column (family), therefore they have the same number of protons.
21.Electromagnetic radiation can take the form of which of the following types of waves
a.Heat
b.Light
c.Ultraviolet
d.All of the above
24.In order to go to a lower energy orbit, an electron
a.Must disappear
b.Must combine with other electrons
c.Lose energy of a specific amount
d.Must be transferred to another atom
25.Please choose the correct sequence that describes the excitement of an atom.
1. Such an electron transition raises the atom from the ground state to the excited state.
2. When energy is added to an atom from an outside source, its electrons move to a higher energy level (orbit)
3. As a result, the atom emits a photon.
4. When the atom is in an excited state, the electron can drop from the higher energy level to a lower energy level.
a.1, 2, 3, 4
b.4, 3, 2, 1
c.2, 1, 4, 3
d.3, 4, 1, 2
how can you find the charge on po4
Answer:
Answer:
Explanation:
I hope it's helpful!
Can someone please explain to me what a Ecologist does for a living? (Or daily in their career?)
ecologists look at relationships between nature, studying the interactions between humans, animal and plants.
Answer:
Ecologists focus on the relationship of organisms within their environment. Ecology is a branch of biology (biology is the study of life). Given the broad scope of ecology, there are multiple sub-disciplines that an ecologist can choose to focus on. Since all living things (plants, animals, microbes) depend on other living things and a healthy environment to survive, ecologists may specialize in one aspect of an ecosystem. Examples include terrestrial (land), aquatic (water), applied (concepts and principles of ecology), conversation (management of biodiversity), and evolutionary (evolution).
Explanation:
Brainliest plz
for 50 points!! im having a bit of trouble haha
Answer:
answer 16.1.) bohr model used to predict bonding abilities2.) electrical charge attraction holds atom together3.) valence electrons are outermost electrons4.) electron cloud - where electrons are foundanswer 17.falsebecause atomic number are numbers of protons
Calculate number of g H3PO3 formed from 53.6 g H2O react with excess PCl3?
PCl3 + H2O → HCl + H3PO3
81.3 g H₃PO₃
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Reaction Molar RatiosUsing Dimensional AnalysisExplanation:Step 1: Define
[RxN - Unbalanced] PCl₃ + H₂O → HCl + H₃PO₃
↓
[RxN - Balanced] PCl₃ + 3H₂O → 3HCl + H₃PO₃
[Given] 53.6 g H₂O
[Solve] x g H₃PO₃
Step 2: Identify Conversions
[RxN] 3 mol H₂O → 1 mol H₃PO₃
[PT] Molar Mass of H - 1.01 g/mol
[PT] Molar Mass of O - 16.00 g/mol
[PT] Molar Mass of P - 30.97 g/mol
Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol
Molar Mass of H₃PO₃ - 3(1.01) + 30.97 + 3(16.00) = 82.00 g/mol
Step 3: Stoich
[S - DA] Set up: [tex]\displaystyle 53.6 \ g \ H_2O(\frac{1 \ mol \ H_2O}{18.02 \ g \ H_2O})(\frac{1 \ mol \ H_3PO_3}{3 \ mol \ H_2O})(\frac{82.00 \ g \ H_3PO_3}{1 \ mol \ H_3PO_3})[/tex][S - DA] Multiply/Divide [Cancel out unit]: [tex]\displaystyle 81.3023 \ g \ H_3PO_3[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
81.3023 g H₃PO₃ ≈ 81.3 g H₃PO₃
the seven continents used to be one huge supercontinent called Ppaonderosa, Panhandle, Pangaea, Panthalassa
Answer:
Pangaea
Explanation:
Answer:
Pangea
Explanation:
Pangaea or Pangea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from earlier continental units approximately 335 million years ago, and it began to break apart about 175 million years ago
How many atoms are in 2.54 mole O?
Answer: 1.505 * 10^24 atoms
========================================================
Work Shown:
1 mole = 6.02 * 10^23 atoms
2.5*(1 mole) = 2.5*(6.02 * 10^23 atoms)
2.5 moles = (2.5*6.02) * 10^23 atoms
2.5 moles = (15.05) * 10^23 atoms
2.5 moles = (1.505 * 10^1) * 10^23 atoms
2.5 moles = 1.505 * (10^1*10^23) atoms
2.5 moles = 1.505 * 10^(1+23) atoms
2.5 moles = 1.505 * 10^24 atoms
This is true for any element. This value is an approximation since there are roughly 6.02 * 10^23 atoms in 1 mole of any element.
[please answer fast!] If the hydroxide ion concentration is 2x10^-3 M, what is the pH of the solution? Show your working.
Answer:
pH = 11.30
Explanation:
pH is defined as -log [H⁺]
To find [H⁺] from [OH⁻] -Concentration of hydroxide ion-, we must use the equilibrium of water:
H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)
Keq = 1x10⁻¹⁴ = [H⁺] [OH⁻]
[H⁺] = 1x10⁻¹⁴ / [OH⁻]
[H⁺] = 1x10⁻¹⁴ / 2x10⁻³M
[H⁺] = 5x10⁻¹²M
pH = -log (5x10⁻¹²M)
pH = 11.30What are mineral acids?
Answer:
mineral acids are obtained from one or more inorganic compounds which is a compound that lacks carbon and hydrogen bonds. Inorganic compound examples include water and carbon dioxide. Something all mineral acids do is form hydrogen ions and the joined together bases when it is dissolved in water.
Explanation:
Write the formula for potassium nitride?
(show work)
CAN SOMEONE PLEASE HELP?
Answer:
It should b KNO3
Explanation:
one Potassium (K) and three Nitrite (NO3)
You are given 0.39 mol of niobium (Nb). How many grams of niobium do you have?
Answer:
36gNb
Explanation:
0.39 mol Nb*92.91g Nb/1 mol Nb=36 g Nb
Mg3N2+3H2O-3MgO+2NH3 If 17 g of magnesium nitride is used, what volume of ammonia gas would be collected at 20°C and 0.989 atm?
Explanation:
what are the unit given for the questions
What is the symbol for Sodium?
Na
S
describe nucleus of atom
Answer:
the nucleus is made up of protons and neutrons
mass-mass problem:
If 25.0 grams of carbon dioxide are used in photosynthesis how many grams of glucose (C6H12O6) could be Produced according
to the following equation : 6CO2 + 6H2O → C6H12O6 + 602
Answer:
17.05 g of glucose
Explanation:
The equation of the reaction is given as;
6CO2 + 6H2O → C6H12O6 + 602
From the equation;
6 mol of CO2 produces 1 mol of C6H12O6
Converting to masses;
CO2:
Mass =Number of moles * Molar mass
Mass = 6 mol * 44 g/mol = 264 g
C6H12O6:
Mass = Number of moles * Molar mass
Mass = 1 mol * 180 g/mol = 180 g
This means 264g of CO2 produces 180g of C6H12O6
25g of CO2 would produce x g of C6H12O6
264 = 180
25 = x
x = 25 * 180 / 264
x = 17.05 g
The melting point of oxygen is -218°C and its boiling point is -183°C. What is the state of oxygen at -200°C?Immersive Reader
it is in a liquid state
Explanation:
how many atoms are in each compound ?
What are periods on the periodic table? How many are there?
Helppp
me plzzz!!!!
Answer:
Explanation:
The sound waves are bocing off the walls.
Which type of model is described below? A scientist thinks of the inside of a tree as being like a giant straw that can suck up water A. Atomic model B. Physical model C. Mathematical model D. Conceptual model
Answer:
B. Physical model
Explanation:
Out of the four of them this is the one that makes the most sense
Why is sterilising the water rarely used in treating the sewage water?
Answer:
Sterilizing the water rarely used in treating the sewage water is described below in details.
Explanation:
Sterilization is the application of a chemical or physical system to eradicate all microorganisms, concluding comprehensive amounts of bacterial content. Heat treatment is the most relevant approach for the sterilization of waste-water that accommodates large levels of masses. well now sterilizing the water is un-usually practiced in managing the sewage water.
Look at the image below:
Mid ocean ridge
Sea towe
Marie Sedie
Osta 7m
WORM
PC
hohe materieur
Tron
Orope
thenosphere
perduta
What type of plate boundary is shown here?
convergent
divergent
transform
Answer:
Divergent
20 words
Answer:
divergent...........................
Explain how you can convert from the number of representative particles of a substance to moles of that substance.
Answer:
the number of representative contain in 1 mol of a substance equals to 6.o2x10^23 particles.Number of representative particles of a substance can be converted to moles of that substance by multiplying it by Avogadro's number as 1 mole=6.023 ×10²³.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number
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How is the rotation of the Sun different from the rotation of Earth?
OThe parts of the Sun rotate at different speeds and the parts of Earth rotate at the same speed.
O The Sun's equator rotates faster than its poles and Earth's equator rotates slower than its poles.
O The Sun's poles rotate faster than its equator and Earth's poles rotate slower than its equator.
O The parts of the Sun rotate in different directions and the parts of Earth all rotate in the same direction
Answer:
The Sun's equator rotates faster than it's poles and Earth's equator rotates slower than it's poles.
Explanation:
Which statements reflect the process of electrolysis? Check all that apply. Water is formed from ions of hydrogen and oxygen. The electrical reactions in a rechargeable battery can be reversed. The cathode becomes the electrode for reduction. The cathode takes on the metal deposits or layers. Decomposition of ores produces separated elements. Decomposition of ores produces low energy products.
Answer:
Decomposition of ores produces separated element.
Answer: it’s b, d, and e
Explanation: i just did it, hope this helps :)