Answer:
Explanation: The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams. This is stated: the molar mass of water is 18.02 g/mol.
Please help I'm not sure what the answers are
Answer:
An element's mass number (A) is the sum of the number of protons and the number of neutrons. The small contribution of mass from electrons is disregarded in calculating the mass number.
Groups of atoms repeat to make up a substance?
True
False
Answer:
ITS TRUE!!!!!
Describe, in terms of subatomic particles, what occurs when a person experiences a static “shock”.
What is a net ionic equation? A. An equation that shows only those particles involved in the reaction, and that is balanced for mass but not for charge B. An equation that shows only those particles involved in the reaction, and that is balanced for both mass and charge C. An equation that describes the flow of oxygen in a combustion reaction D. An equation that shows the cations as reactants and the anions as products
Answer:
B. An equation that shows only those particles involved in the reaction, and that is balanced for both mass and charge
Explanation:
A net ionic equation is a chemical equation that will only show the elements, compounds, and ions that are directly involved in the chemical reaction. It comes from the balanced molecular equation and should be balanced by both mass and charge.
please help
Why does a smoke detector use alpha radiation rather than beta or gamma radiation?
Answer:To be honest i dont know
Explanation:
e
Answer:
Explanation:
Alpha radiation ionizes the air. When smoke interaccts with the ionized particles it causes the alarm to sound.
8. Extinction of a species could result from
*
1
evolution of a type of behavior that produces greater reproductive success
synthesis of a hormone that controls cellular communication
limited genetic variability in the species
fewer unfavorable mutations in the species
Answer:
Limited Genetic Variability
Explanation:
its 3
What is FALSE about nitrogen gas and carbondioxide?
1- Both are compounds
2- Both are gases
3- Elements in both substances are non-metals
4- Both are made up of atoms
Answer: Both are compounds
Explanation:
[tex]\text{N}_{2}[/tex] is an element, not a compound.
Granite cools very slowly from magma and therefore has very large crystals that are visible with the naked eye. Granite can be classified as —
A.
an igneous rock.
B.
a metamorphic rock.
C.
a sedimentary rock.
D.
an extrusive rock.
Answer:
A
Explanation:
Igneous rock forms from cooled lava
If a nuclear reactor were to have a meltdown, radioactive materials could escape in the form of gases from the reactor into the atmosphere and harm humans and the environment. One safety system that might be able to prevent such an escape is a:
A containment building.
hope this helpedddd
How many grams of water react to form 4.50 moles of Mg(OH)2?
MgO(s) + H20(1)
Mg(OH)2(s)
Answer: mass of water is 81.1 g
Explanation: from reaction eguation you see there are equal amounts of water and Mg(OH)2. Then amount of water is 4.50 mol. Molar mass of water is 18.016 g/mol.
Mass m= n·M= 4.50 mol· 18.016 g/mol = 81.1 g
The number of grams of water reacting to form a mass of water is 81.1 g.
What is mass?Mass is the quantity of matter in a physical body.
The given reaction is
MgO(s) + H₂O(1) → Mg(OH)₂(s)
The number of moles is equal in both sides
The moles of water is 4.50
The molar mass of water is 18.016 g/mol
mass × molar mass
4.50 × 18.016 = 81.1 g.
Thus, the number of grams of water reacting to make a mass of water is 81.1 g.
Learn more about mass
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How are the sun and Earth's moon different? (2 points)
a
The sun is a ball of gases that revolves around Earth, while the moon is the center of the solar system.
b
The sun is a ball of rock and gas, while the moon is a ball of rock that revolves around the sun.
c
The sun is the center of the solar system, while the moon is a ball of rock that revolves around Earth.
d
The moon is the center of the solar system, while the sun is the center of the Milky Way.
what is velocity measured in?
Answer:
units of length per time
Explanation:
The use of uranium-238 to determine the age of a geological formation is a beneficial use of
O 1.
nuclear fusion
2.
nuclear fission
3.
radioactive isomers
4.
radioactive isotopes
Answer:
4- radioactive isotopes
Explanation:
I don't remember exactly but this question was on the regents
Uranium-238 is a non- fissile element. It is a radioactive isotope that can be best used to determine geological formations. Thus, option 4 is correct.
What are radioactive isotopes?Radioactive isotopes are elements that have an unstable atomic nucleus and can undergo radioactive decay to produce new particles and energy. They have the same atomic number as that of their parent species.
Isobars are a substance that has atomic mass and do not include uranium. Nuclear fusion and fission are the processes of nuclear energy that combine or splits the unstable nucleus to form a new particle.
Therefore, option 4. Uranium-238 is a radioactive isotope.
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2 questions. will give brainliest if i can figure out how
What happens to the electrons of a reducing agent during a reaction?
a.Electrons are gained
b.Electrons are lost
c.Electrons are held
d.Electrons are doubled
When is a substance reduced during an oxidation reduction reaction?
a.After one substance is oxidized
b.Before one substance is oxidized
c.Same time as one substance is being oxidized
d.Only oxidation occurs
1= b. electrons are lost
2= a. after one substance is oxidized
14. A 70 N tight rope walker is walking 20 meters above ground. About how much Gravitational Potential Energy does the performer have? 1,400 J 1,200 J 800 J
Answer:
It is 1,400 j
Explanation:
That is what i know
Answer:
1,400J
Explanation:
the formula for calculating Gravitational Potential Energy is mass×gravitational field strength×height
70×10×20=1,400
Predict the electron pair geometry and the molecular structure of each of the following molecules or ions: (a) ClNO (N is the central atom); Determine: electron-pair geometry ; molecular structure ; (b) CS2; Determine: electron-pair geometry ; molecular structure ; (c) Cl2CO (C is the central atom); Determine: electron-pair geometry ; molecular structure ; (d) Cl2SO (S is the central atom); Determine: electron-pair geometry ; molecular structure ; (e) SO2F2 (S is the central atom); Determine: electron-pair geometry ; molecular structure ; (f) XeO2F2 (Xe is the central atom); Determine: electron-pair geometry ; molecular structure ; (g) ClOF2 (Cl is the central atom); Determine: electron-pair geometry ; molecular structure ;
Answer:
See explanation
Explanation:
In ClNO , nitrogen is the central atom here. The central atom has a tetrahedral electron pair geometry and a lone pair on the nitrogen atom. Due to the lone pair, the electron pair geometry is now trigonal pyramidal.
The molecule CS2 has a linear molecular geometry. There are four electron groups around the central atom hence the electron pair geometry is tetrahedral but the molecular geometry results from the repulsion of the two double bonds.
The electron domain geometry for Cl2CO is tetrahedral since there are four electron pairs around the central atom. However, the molecular geometry is trigonal planar due to the sp2 hybridization of the central carbon atom.
The electron domain geometry of Cl2SO is tetrahedral due to the four electron pairs around the central atom. However, due to the lone pair on sulphur, the molecular geometry is triagonal pyramidal.
In SO2F2, sulphur the central atom is surrounded by four electron pairs which are all bonding groups hence both the molecular geometry and the electron pair geometry is tetrahedral.
In XeO2F2, the central atom is Xe. There are five electron pairs around the Xe central atom four of which are bonding groups. The electron domain geometry and molecular geometry is trigonal bipyramidal.
For ClOF2 , the central atom Cl is surrounded by four electron pairs hence the electron pair geometry is tetrahedral but it is an AX3E(three bonding groups and one lone pair are present in the structure) specie hence it is trigonal pyramidal.
how can we find out the mass of the marble
In a collection of marbles, 25% of the marbles have a mass of 5.00 g and 75% of the marbles have a mass of 7.00 g. The average mass of a marble is 6.50 g.
1. A sample of oxygen gas has a volume of 150 ml when its pressure is 440 mmHg. If the pressure is
Increased to standard pressure and the temperature remains constant, what will the new volume be?
Answer:86.84
Explanation:
How much water needs to be added
to 55 mL of 3.0 M stock solution to
produce a .75 M solution?
Answer:
165 ml
Explanation:
We are given;
Initial volume; V_a = 55 ml
Initial molarity; M_a = 3 M
Molarity of desired solution; M_b = 0.75 M
Volume of desired solution; V_b = (55 + x) ml
Where x is the volume of water to be added.
To solve for V_b, we will use the equation ;
M_a•V_a = M_b•V_b
V_b = (M_a•V_a)/M_b
V_b = (3 × 55)/0.75
V_b = 220 mL
Thus;
(55 + x) = 220
x = 220 - 55
x = 165 mL
Answer:
gotta concert mL to L
3.0=mol/0.055( you multiply morality and liter)
0.165 mol
you divide the mole by the other given molarity
0.165/0.75= 0.22 L
0.22 *1000= 220 mL
Explanation:
When a 0.3546 g of vanadium metal is heated in air, it reacts with oxygen to achieve a
final mass of 0.6330 g. Calculate the empirical formula of this vanadium oxide
Answer:
V2O5 is the empirical formula of vanadium oxide
Explanation:
The molecular mass of Vanadium is 50.949 g/mol
Number of moles of vanadium = 0.3456 g/50.949 g/mol = 0.00696 moles
The molecular mass of Oxygen is 16.0 g/mol
Number of moles of Oxygen = (0.6330 – 0.354) g/16 g/mol = 0.0174 moles
Emperical formula
V (0.00696 moles/0.00696 moles) O (0.0174 moles /0.00696 moles)
V 1 O2.5
Multiply by two get a whole number
V2 O5
Choose all the nucleophiles.
Choose one or more:
CH3SNa
NaNH2
H3O+
CH3OH
CH3CH2CH3
NH4+
OH-
(CH3)3CLi
Answer:
CH3CH2CH3
(CH3)3CLi
CH3SNa
Explanation:
Sven perform this reaction with 15.0 grams of sodium sulfate and an excess of iron (III) phosphate to make iron (III) sulfate and sodium phosphate. In the actual experiment, 10.0 grams of sodium phosphate are experimentally made, what is the percent yield?
2FePO4+3Na2SO4-->Fe2(SO4)3+2Na3PO4
Answer:
85.5%
Explanation:
To get the experimental value, you need to convert 15.0 grams of Na2SO4 to grams of Na3PO4. You do this with stoichiometry.
Convert grams of Na2SO4 to moles with molar mass. Then convert to moles of Na3PO4 with the mole-to-mole ratio according to the balanced chemical equation. Then convert moles of Na3PO4 to grams with the molar mass.
15.0 g Na2SO4 x (1 mol/142.04 g) x (2 Na3PO4/3Na2SO4) x (163.94 g/1 mol) = 11.7 g Na3PO4
Percent Yield = (actual value/experimental value) x 100
Actual Value = 10.0 g
Experimental Value = 11.7 g
10.0g/11.7 g = 85.5%
What does thermal energy refer to?
A. The chemical energy in reactions
B. The heat transferred between objects
C. The kinetic energy of particles within a system
D. The energy obtained from the sun
SUBMIT
Answer:
c
Explanation:
Thermal Energy has been the type of energy that refers to the kinetic energy of particles contained in a system. Hence, the correct option is (C).
What is thermal energy?
Thermal energy is the energy contained within a system as a result of its temperature. Thermodynamics, a branch of chemistry, states how heat is transmitted through multiple systems and how work is done in the process by the virtue of the first law of thermodynamics.
The thermal energy speeds the movement and collision of the particles present within the system. It is found in electric heat, geothermal, coals, etc. It is due to the kinetic energy that allows the movement of the particles.
Therefore, option C. the kinetic energy contained in the particles results in thermal energy.
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How many moles are in 56 L of CO2?
Answer:
we have four moles in 56L of co2
The annual production of sulfur dioxide from burning coal, fossil fuels,
auto exhaust, and other sources is about 130 million tons. When solid sulfur
reacts with oxygen gas it produces gaseous sulfur dioxide. What is the mass
in grams of sulfur that is needed to produce 2.30 Kg of sulfur dioxide?
*Don’t forget from your metric you were given that 1 Kg = 1000 g.
Answer:
1150g
Explanation:
The equation for producing sulphur dioxide is [tex]S + O_{2} ==> SO_{2}[/tex]
Looking at the ratios, you need 1 mole of sulphur for every 1 mole of sulphur dioxide
Sulphur dioxide has a molar mass of 32 + (2 x 16) = 64g
2.30 x 1000 = 2300
2300 / 64 = 35.9375
35.9375 x 32 = 1150g of sulphur
18) What is the following number representing: 10m/s West *
3 points
Force
Acceleration
Mass
Area
Pressure
Velocity
Speed
Impulse
Momentum
Speed
Explanation:
The distance travelled by a body per unit time
help me please
ive been here for hours
Answer:
A- Before the mechanic left, the molecules were moving away from each other. When she returned, they were moving around each other.
Explanation:
Brainliest?
Describe reflection, refraction, and absorption.
Answer:
Refraction is the bending of a wave when it enters a medium where its speed is different, like going from the air (gas) to a glass of water (liquid). Absorption is when light energy penetrates an object. Typically this energy is then converted to heat.
One tank of gold fish is fed the normal amount of food once a day. A second tank is fed twice a day. A third tank is fed four times a day during a six week study. The fish's weight is recorded daily. What is the problem and the hypothesis?
Answer:
Problem: What is the effect of the amount of fish feed on the mass of goldfish?
Hypothesis: I think that feeding the goldfish four times a day will greatest increase in the mass of the goldfish.
Explanation:
The problem tends to ask question to which the research is conducted. It open ways for ideas towards a particular topic.
While the hypothesis is a tentative or assumed stand on a subject. It is further tested through an experiment or survey and if after many trials it gives same results and the obtained results is concordant with the hypothesis, the hypothesis will then become accepted and a theory or law is formed thereafter.
make this and tell me how u like it its fat lady from hairy pawter find the pics on elgoog or use mine movie and site was changed its on scratch a web
Answer:
are u brocken
Explanation: