Sodium has a mass number of 23amu. Since sodium has 11 protons, the number of neutrons must be 23 – 11 = 12 neutrons.
PLZ HELP which ia an example of a scientist using a physical model to describe a river
A. the scientists thinks of a river like a flow of electrons
B. the scientists builds a model of the river using plastic and a hose
C. the scientists writes an equation that describes the flooding of the river
D. the scientists uses a computer to predict how much water will flow
in the photoelectric effect, what happens when light hits the metal
Answer:
electrons are knocked off atoms, causing electricity to flow.
Explanation:
How nephthalene can be purified by sublimation
Answer:
sublimation. During this process, naphthalene being sublime changes into vapours leaving behind impurities. Vapour can be cooled by condensation. This process is very helpful in separating a volatile solid from a non-volatile solid.
ASAP
Which of the following gases will have the highest rate of effusion at a given temperature?
Cl2
He
O2
Ne
Answer:
chlorine Will be at highest
can you solve this.
I need it.
:) :):)
Answer:
12
45
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True or false, The universal gas constant, R, is . 0821 when we use mm Hg as our unit for pressure
Answer:
This is true.
Explanation:
R should be 0.0821
Good luck!
Which missing item would complete this alpha decay reaction?
21CF-247 Cm +
Answer:
the atomic number decreased in 2, from 100 to 100 - 2 = 98. 3) Hence the formed atom has atomic number 98, which is californium, Cf, and the isotope is californium - 253. 4) The item that completes the given alpha decay reaction is: ₉₈²⁵³ Cf.
Explanation:
Name the property of salt investigated in the above experiment
which experiment please involve a clip
11. A mixture of magnesium powder and lead (II) Oxide will react vigorously when heated but no reaction occurs when a mixture of magnesium oxide and lead powder are heated, a) Explain the observation. b Which of the two substances, magnesium or lead(IT) Oxide is; i) Oxidized in the reaction? ii) Oxidizing agent? C Which is the most reactive metal Please helpA
Answer:
17
Explanation:
i need points
What happens when acetylene reacts with silver powder?
Can someone do these? Brainliest included
Answer:
Explanation:
6. p⁺ e⁻
Ca²⁺ 20 18
F⁻ 9 10
O²⁻ 8 10
Na⁺ 11 10
7. Physical properties of matter are properties that can be measured or observed without matter changing to an entirely different substance. These include odor, boiling point, melting point, density, electrical conductivity and heat conductivity.
Separation of mixture:
Chromatography involves solvent separation on a solid medium.
Distillation takes advantage of differences in boiling points.
Evaporation removes a liquid from a solution to leave a solid material.
Filtration separates solids of different sizes.
Funnel partitioning with solvents. Solvent dissolves one component but not the other.
8.Bulk Elements => Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur & Phosphouous
Microminerals are those minerals needed in less than 100 mg quantities. Trace minerals or trace elements are usually needed in microgram quantities. Microminerals include iron, zinc, copper, iodine, fluoride, chromium, cobalt, selenium, manganese, and molybdenum.
Diatomic Molecules => H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂
9. Electron Configurations
Na: 1s²2s²2p⁶3s¹ => valence = 3s¹
N: 1s²2s²2p³ => valence = 2s²2p³
Al: 1s²2s²2p⁶3s²3p¹ => valence = 3s²3p¹
Valence is the highest principle quantum number (or, principle energy level ~ ring) in the electron configurations.
10.moles of glucose = 450g/180.16 g/mol =2.50 moles
C₂H₆O₂ = 2(12) + 6(1) + 2(16) = 24 + 6 + 32 = 62 g/mole
write the importance of exothermic reactions
Answer: An exothermic reaction is a "reaction for which the overall standard enthalpy change ΔH⚬ is negative." Exothermic reactions usually release heat and entail the replacement of weak bonds with stronger ones.
Exothermic reactions are important to forensic sciences and particularly to fire and explosion investigation. When a chemical reaction requires heat (rather than producing it) and results in cooling down the surroundings, it is conversely called endothermic.
Example-
Respiration is a series of exothermic reactions that occur in the mitochondria of living cells in order to release energy from food molecules. This energy can then be used to produce heat, for movement, growth, reproduction and active uptake.
Hope it helps
ASAP worth 15 points also
How many chlorine (CI) atoms are in Methylene?
Answer:
None
Explanation:
Methylene is an organic compound and organic compounds consist of hydrogen atoms and Carbon atoms in n this case Methylene(CH2) has one carbon and two hydrogens .
Answer: methylene doesn't contain CL(chlorine) atoms
Explanation: the chemical formulae for Methylene is CH2
which means it contains only carbon and hydrogen atoms which is 1(one) carbon 2(two)hydrogen atoms
HOPE THIS HELPS!!
solubility of sodium chloride in water at 27 degree celsius is 22.7 in hundred ml of water the density of water is 1.0 gram per ml calculate the concentration of sodium chloride in term of mass percentage when dissolved in 500 ml of water
please tell me correct answer with solution
Answer:
of what grade it is of??
Explanation:
tell me then ill answer
what the recipe of momo
Answer:
Down is the recipe for momo..
Explanation:
recipe..
. Sieve the wheat flour carefully to remove lumps.
. Add water and knead the flour well to prepare a dough
. Remove the skin of the boiled potato ,cut into small pieces
. Heat the cooking oil in frying pan, and fry the pieces of onions cabbage green chili tomato pea etc.
. Prepare a mix veg stuffing by mixing potato other vegetables , green coriander and salt.
. Prepare a small balls of dough and roll it out of belna.
. Put 10 gm of mix vegetables stuff in the center of rolled dough and close it from all the sides to make a small ball.
. steam the momo for 10-15 minutes. After that it will be ready to serve.
. A sauce or pickle is usually eaten with momo.
Answer:
Explanation:
Sieve the wheat flour carefully to remove lumps.
I NEED HELP ASAP!!!
All of the following are examples of ways to increase mechanical advantage EXCEPT:
Select one:
a.adding more threads to a screw
b.making a wheel larger than an axle
c.increasing the length of a ramp
d.increase the steepness of a ramp
Hydrogen bromide is found in volcanic gas. What is the chemical formula for
this compound?
Answer:
Hydrogen bromide, anhydrous appears as a colorless gas with a pungent irritating odor. Corrosive. Heavier than air. Prolonged exposure to fire or intense heat may result in the violent rupture and rocketing of the container. Long-term exposure to low concentrations or short-term exposure to high concentrations can result in adverse health effects from inhalation. Used to make other chemicals and as a catalyst in the manufacture of chemicals. Rate of onset: Immediate Persistence: Minutes to hours Odor threshold: 2 ppm Source/use/other hazard: Chemical manufacturing industry; very corrosive.
Explanation:
HBr
Consider the terms elements, compounds, and mixtures. What do you think each of
these is?
Answer:
Explanation:
Element -
It is the basic unit of matter, which cannot be broken down into substances by any way but can be combined to form new substances.
It is a pure substance.
It classifies into metals, non-metals, metalloids and noble gases.
Example - Hydrogen, Carbon, Oxygen
Compounds -
It is a combination of two or more elements.
It is a pure substance.
Through chemical reactions, they can be broken down into metals.
Example - Water, Carbon dioxide
Mixtures -
It is a combination of two or more elements or compounds or both.
The substances combined in a mixture are in a particular ratio.
Example - Chalk powder, Washing Soda
Small quantities of spilled acids can be made safe with *
1 point
o gasoline.
alcohol.
water.
sodium bicarbonate solution.
Answer:
sodium bicarbonate solution
Froming a hypothesis is the first step of the scientific methhod true or false
Answer:
The first step in the Scientific Method is to make objective observations. These observations are based on specific events that have already happened and can be verified by others as true or false. Step 2. Form a hypothesis.
Answer:
False
Explanation:
The first step of the scientific method is to make an observation.
Question 22 of 30
What is the balanced form of the chemical equation shown below?
C6H1206(s) + O2(g) → H2O(l) + CO2(9)
A. CH 0(s) + O2(g) → H2O(1) + CO2(g)
B. CoH1206(s) + O2(g) → 12H2O(l) + 6CO2(g)
C. C6H1206(s) + O2(g) → H20(1) + CO2(g)
D. CoH 206(s) + 602(g) → 6H2O(l) + 6CO2(g)
SU
Answer:
C6H12O6+6O2--->6CO2+6H2O
Explanation:
So I went through all the answers and could not find the right one amongst. If I'm not wrong the reaction above is the reaction for respiration. The nearest answer is D but unfortunately the first reactant isn't in accordance with that which the question has given.
How many moles of Ba(OH)2 are present in 205 mL of 0.600 M Ba(OH)2?
Answer:
Explanation:
0.180 moles of Ba(OH)2 are present.
Answer:
[tex]\boxed {\boxed {\sf 0.123 \ mol \ Ba(OH)_2}}[/tex]
Explanation:
Molarity is a measure of concentration in moles per liter. It is calculated using the following formula:
[tex]molarity= \frac{moles \ of \ solute}{liters \ of \ solution}[/tex]
The molarity of the solution is 0.600 M Ba(OH)₂. 1 molar (M) is also equal to 1 mole per liter, so the molarity is 0.600 moles of Ba(OH)₂ per liter.
The volume of the solution is 205 milliliters, however, we need to convert the volume to liters. Remember that 1 liter contains 1000 milliliters.
[tex]\frac { 1 \ L}{1000 \ mL}[/tex][tex]205 \ mL * \frac { 1 \ L}{1000 \ mL} = \frac {205}{1000} \ L = 0.205 \ L[/tex]Now we know the molarity and volume, but the moles are still unknown.
molarity = 0.600 mol Ba(OH)₂/ L moles of solute = x liters of solution = 0.205 LSubstitute these values into the formula.
[tex]0.600 \ mol \ Ba(OH)_2 /L = \frac{x}{0.205 \ L}[/tex]
We are solving for x or the moles of solute, so we must isolate the variable. It is being divided by 0.205 liters. The inverse of division is multiplication. Multiply both sides by 0.205 L.
[tex]0.205 \ L *0.600 \ mol \ Ba(OH)_2 /L = \frac{x}{0.205 \ L} * 0.205 \ L[/tex]
[tex]0.205 \ L *0.600 \ mol \ Ba(OH)_2 /L =x[/tex]
The units of liters cancel.
[tex]0.205 *0.600 \ mol \ Ba(OH)_2 =x[/tex]
[tex]0.123 \ mol \ Ba (OH)_2 = x[/tex]
The original measurements had at least 3 significant figures. Our answer currently has 3 sig figs, so we don't need to round.
There are 0.123 moles of barium hydroxide.
im doing a escape room and i dont know what the answer is
Answer:
thats pink floyds album cover LOL
but the answer is to prism
hope this helps :)
hii pls help me to balance the equation thanksss
Answer:
3Fe(s)+2O2(g)---->Fe3O4
this way you will have 3irons on both sides and 4 oxygens.
I hope this helps
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\pmb{\red{\sf{3Fe(s) + 2O_{2}(g)\dashrightarrow Fe_{3}O_{4}(s)}}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
which of the following is not good conductor of heat?
1-brass
2-stainless steel
3-bakelite
4-silver
Answer:
b. stainless steel
Explanation:
b) stainless steel is not good condoctor of heat
A database search would be the best method of gathering which type of data?
data?
Utilizing a database search would be most effective for obtaining the data related to registered voters. The Option D.
What method is optimal for collecting total registered voters' data in a country?A database search proves invaluable when seeking to retrieve specific information such as the total number of registered voters in a country. By querying the database with the appropriate parameters, you can efficiently extract accurate and up-to-date voter registration figures.
This method streamlines data collection by ensuring accuracy and reducing the potential for errors associated with manual collection processes.
Read more about database
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Which of the following is the best definition of ethics?
A. The maintenance of a stable internal environment
B. Response to external stimuli
C. A set of guidelines for fair conduct during an experiment
D. A multistep process whose last step controls what happens in an
earlier step
Answer:
C
Explanation:
I believe the answer is C.
Which of the following represents an endothermic reaction?
Select one:
a. S(s) +O2(g) → SO2(g) ΔH = -297kJ
b. 2NO2(g) → N2(g) + 2O2(g) + 33.8kJ
c. N2(g) + 2O2(g) + 90.4kJ → 2NO2
d. N2H4(g) + O2(g) → N2(g) +2H20(g) + 627.6 kJ
B because decomposition reactions are often caused by the application of heat to break up the bonds within the molecules, which will form the molecules that made up the decomposed molecule.
What would you need to do to calculate the molality of 10 g of NaCl in 2 kg of
water?
A. Convert the 2 kg of water to liters of water.
O B. Convert the 10 g of NaCl to moles of NaCl.
C. Convert the 2 kg of water to moles of water.
O D. Convert the 10 g of NaCl to kg of NaCl.
Answer:
O B. Convert the 10 g of NaCl to moles of NaCl.
Explanation:
The formula for finding the molality is m=moles of solute/kg of solvent. The solute for this question is NaCl and the solvent is water.
(10g NaCl)(1 mol NaCl/58.44g NaCl)=0.1711 mol NaCl
58.44 is the molar mass of NaCl
m=0.1711 mol NaCl/2 kg H2O
m=0.085557837
