Answer:
216/84 Po + 4/2 He a
Explanation:
Answer:
Problem: Polonium-210, 210Po, decays to lead-206, 206Pb, by alpha emission according to the equation 21084Po → 20682Pb + 42He
Explanation:
Which of the following is made of an element?
Rust
A rose
diamond
Blue paint
O None of these
The half-life of the radioactive isotope silver-104 is 30 minutes. After how many minutes will about 20 grams of a 40-gram sample of the silver-104 isotope remain?
Select one:
a. 0
b. 60
c. 90
d. 30
Answer:
d
Explanation:
The amount of time it will take for the 40g sample to get cut in half is 30 minutes
Which fatty acids are considered essential fatty acids?.
Answer:
alpha-linolenic acid and linoleic acid
Explanation:
Hope this helps!
A chemist carefully measures the amount of heat needed to raise the temperature of a sample of from to. The experiment shows that of heat are needed. What can the chemist report for the molar heat capacity of ? round your answer to significant digits.
Answer:
Are there any options or starting points for this question?
Explanation:
They all have the same choices but one of them its not gonna be used.
Answer:
limiting reactant
Explanation:
it is consumed totally
What is the molar mass of a gas if 0. 473 g of the gas occupies a volume of 376 ml at 23. 0°c and 1. 90 atm?.
Answer:
The molecular weight of the unknown gas is 16.1 g/mol.
If 4.00 moles of fluorine are reacted with excess HBr, how many grams of bromine will be formed
The mass of bromine that would be formed is 639 g
StoichiometryFrom the question,
We are to determine how many grams of bromine would be formed
First, we will write the balanced chemical equation for the reaction,
The balanced chemical equation for the reaction is
F₂ + 2HBr → 2HF + Br₂
This means, 1 mole of fluorine reacts with 2 moles of HBr to produce 1 mole of bromine.
Then,
4.00 moles of fluorine will react with excess HBr to produce 4.00 moles of bromine.
Therefore,
The number of moles of bromine produced is 4.00 moles
Now, for the mass of bromine formed,
Using the formula,
Mass = Number of moles × Molar mass
Molar mass of bromine = 159.808 g/mol
Then,
Mass of bromine formed = 4.00 × 159.808
Mass of bromine formed = 639.232 g
Mass of bromine formed ≅ 639 g
Hence, the mass of bromine that would be formed is 639 g.
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Please help me to do the warm up
Why is it important for lab safety to know the proper names of equipment in a lab
Answer:
Knowing your lab equipment and their names will aid in having a successful experiment and may help in correcting errors.
If you do not know your lab equipment, that will only result in having a lack of knowledge of the equipment or not knowing how to correct a mistake in an experiment.
Explanation:
Hope I helped.
What is the law of conservation of mass?
A. The total mass of materials present after a chemical reaction is the same as the total mass present before the reaction.
B. In a given compound, the relative numbers and kinds of atoms are constant
C. If two elements A and B combine to form more than one compound, the masses of B that can combine with a given mass of A are in the ratio of small whole numbers.
D. Each element is composed of extremely small particles called atoms.
Answer:
A. The total mass of materials present after a chemical reaction is the same as the total mass present before the reaction.
Explanation:
Law of conservation states that whatever mass you start with you will end with, mass cannot be gained or lost
Imagine that the sun disappeared from the universe tomorrow. Which sphere or spheres would this affect?(1 point)
The earth and other planets start drifting into space.
What happen if sun disappear?If the sun disappear from the universe, then Earth would be drawn to a new center of gravity. The gravity of Earth and the other planets of the solar system adversely affected due to no constant supply of energy from the sun which leads to drifting of earth into space.
In conclusion, the earth and other planets start drifting into space.
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Under what conditions does the Ideal Gas Law not apply and gases are considered real? Check all that apply.
high pressure
low pressure
high temperature
low temperature
From what we know, we can confirm that the ideal Gas Law does not apply and gases are considered real under conditions of low temperature and high pressure.
What is the ideal gas law?This law is used to describe how gasses will behave under normal conditions. However, it is not always accurate in certain conditions, the requirement for conditions to be ideal resulted in the name of the ideal gas law. This law fails at low temperatures and high pressure due to the low volume occupied by the gas under these conditions.
Therefore we can confirm that the ideal Gas Law does not apply and gases are considered real under conditions of low temperature and high pressure.
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Answer:
A and D
Explanation:
which of the following is the poorest conductor electricity
Calcium
silicon
cobalt
sodium
fluorine
Answer:
Fluorine
Explanation:
It is a non-metal does not conduct electricity
The poorest conductor of electricity is fluorine.
Why fluorine is the poorest conductor of electricity?
All of these are metals and metalloids so they are the good conductor.
Calcium
silicon
cobalt
sodium
Fluorine is a nonmetal so it is not a good conductor.
What is an electrical conductor?A conductor is a material that allows the flow of charge (current electricity).In a conductor, there is a free electron in a valance cell.the energy gap between the valance shell and conduction is small.In general, all metals and a few metalloids are good conductors.Nonmetals do conduct electricity because the energy gap between the valance band and conduction is very high.so there is n flow of charge.Learn more about conductor here:- https://brainly.com/question/24154868
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If you have 60 moles of HCl, what should the volume of solution be to make a 10 M solution?
Answer:10
Explanation:
Multiply the volume by the density to get the mass.
Divide the mass by the molar mass to get the number of moles.
What happens when a neutral object is brought near a positive object?
Answer:
stick together like magnets
Explanation:
Answer:
If a positively charged body is brought near to a neutral or uncharged body, it induces a negative charge on the near side and a positive charge on the far side of the neutral object. This creates a force of attraction between the two bodies.
empirical or molecular? (C12H6)
empirical or molecular? (C2H4O)
empirical or molecular? (C8H8S4)
Answer:
C12H6 : Molecular
C2H4O : Empirical
C8H8S4 : Molecular
Explanation:
Molecular formula : tells you the exact number of atoms of each element are in a compound. If the number of elements can be simplified it is molecular.
Empirical formula : tells you the most reduced ratio of elements in a compound. If the number of elements is already in it's simplest form it's likely empirical.
C12H6 - this is molecular because C12H6 can further be simplified to C2H
C2H4O - this is empirical because C2H4O cannot further be simplified
C8H8S4 - this is molecular because C8H8S4 can further be simplified to C2H2S
Why do you not fill you car tires with just oxygen?
Answer:
in text
Explanation:
But the main reason for using pure nitrogen is resistance to leakage. Nitrogen molecules find it harder to sneak out through the tire past the rubber molecules than oxygen molecules. This makes nitrogen a good bet for race car, aircraft and heavy-duty equipment where precise or constant pressure is critical.
BRAINLIEST PLEASE !!!!
How many moles of iron are present in 3.15 × 1024 atoms of iron?
Answer:
5.23 moles
Explanation:
Hope this helps!
Two changes are described below.
A green banana turns yellow and ripens.
A layer of rust forms on an iron nail.
Which statement is true about the two changes? (5 points)
Group of answer choices
Both are chemical changes because new substances are formed.
Both are physical changes because only the physical state of the substances change.
A is a physical change due to a change of state, but B is a chemical change because new molecules are formed.
A is a chemical change due to a change of state, but B is a physical change because new molecules are formed.
Answer:
Both are chemical changes because new substances are formed.
Explanation:
in both examples new substances are formed, meaning it is a chemical chang. It cannot be a physical change since it doesn’t involve a chnage in its shape, volume, length, or mass
To solve this, we must know each and every concept behind chemical change and physical change. Therefore, thee correct option is option A that is both are chemical changes because new substances are formed.
What is chemical change?
Chemical change is a reaction in which forming and breaking of new bonds take place. One molecule completely converted to totally different molecule. The number of atoms remains same.
A physical change is characterized by a differences in physical attributes. Melting, transformation to a gas, changes in strength, change in durability, changes in crystal structure, texturing change, shape, color, volume, and density are all examples of physical qualities. Tempering steel to make a knife blade is an instance of a physical change.
One famous example of chemical change is iron rusting. The arrangements , odor and colour of atoms in products are very much different from reactant. Chemical change are mostly irreversible in nature. Ripening of banana is also a chemical change.
Therefore, thee correct option is option A that is both are chemical changes because new substances are formed.
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A 5.00 kg weight is placed on a digital scale. The scale reads 4.98 kg. What
is the error of the scale measurement?
The error of this scale measurement is equal to 0.02 kg.
Given the following data:
Actual measurement = 5.00 kg.Measured value = 4.98 kg.To calculate the error of the scale measurement:
What is measurement?Measurement can be defined as an act (process) through which the weight, size, magnitude or distance traveled by an object or body is taken, especially for the purpose of an experiment.
Mathematically, the error of a scale measurement is given by this formula:
[tex]Error = Actual \;measurement-Measured \;value[/tex]
Substituting the given parameters into the formula, we have;
[tex]Error = 5.00-4.98[/tex]
Error = 0.02 kg.
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When New York receives the most direct rays of the sun
Answer:
At noon
Explanation:
The sun at solar noon reaches its highest point when it is due South.
Which substances have Delta. Hf = 0 kJ/mol by definition? Select all that apply. O2(g) N(g) H2O(l) Br2(l) Fe(s) He(g).
The substances that have Delta Hf = 0 kJ/mol are O2(g), Br2(l), He(g), Fe(s).
What is delta Hf = 0?Delta Hf = 0 is the standard enthalpy of any element in its most stable form is equal to zero.
When enthalpy is negative, the delta Hf is minus zero, which means the system releases heat.
When the system gains heat, the delta Hf is positive.
Thus, the substances are O2(g), Br2(l), He(g), Fe(s).
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Answer:
1,4,5,6
Explanation:
number of protons in nucleus of magnesium atom????
Single and double replacement reactions practice WS CuCl2 +
F2 »
CuF2
+
Cl2
What are some of the difficulties in identifying particular drugs? Why is it important for forensic scientists to be able to identify particular drugs?
Answer:
The forensic scientist must be able to tell the difference between the substances.
Explanation:
It is important for forensic scientists to be able to identify particular drugs so they have evidence for the case that a certain drug was present.
The goal of forensic drug chemistry is to determine whether the material submitted contains an illegal substance.
write the empirical formula for C2H4O8
Answer:
CH2O4
Explanation:
empirical formula for C2H4O8 is CH2O4
Pls help one chemistry question :/
In the following reaction, the energy of the reactants is 860 kJ/mol and the bond energy of the products is 680 kJ/mol. What is the total energy of the reaction? Is the reaction endothermic or exothermic?
Answer:
the anserw should be 665KJ
What property is being measured in the image??
A. mass
B. Density
C.Volume
D.Height
Answer:
I'm pretty sure that the answer is c
1. What is a gene?(1 point)
A. a structure that contains many chromosomes
B. a section of DNA that encodes a specific protein
C. a large molecule that performs a specific function
D. a point that joins two halves of a chromosome
A gene is the basic unit of an organism. Gene is encompassed inside the nucleus of a cell where all the chromosomes and DNAs are located. Thus option A is correct.
What is chromosome?Chromosomes are genetic materials contained in a gene inside the nucleus of a cell. There are different number of chromosomes in each level of organisms.
Chromosomes are made of proteins and DNA (deoxyribonucleic acid). it is a thread like structure having a knot in the center. In human beings there are 23 pairs of chromosomes in each cell.
Chromosomes are transferred to the offspring from the parents and thus they are the genetic material inherited from the parents. Thus gene is the functional unit of heredity. Genes codes each proteins and are responsible for the characteristics of each organism.
Therefore, gene is a structure that contains many chromosomes. Hence, option A is correct.
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What are comets made of?
A. Dust, sand, and hydrogen
B. Rock, metal, and liquid water
C. Dust, metal, and helium
D. Rock, dust, and ice
SUBMIT
Answer:
C. Rock, dust, and ice.
Explanation:
Comets are frozen leftovers from the formation of the solar system composed of dust, rock, and ices.