An atom is the smallest unit of ordinary matter that forms a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small, typically around 100 picometers across
The nucleus (center) of the atom contains the protons (positively charged) and the neutrons (no charge). The outermost regions of the atom are called electron shells and contain the electrons (negatively charged)
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If you have 1.2754x1020 molecules of Barium nitrate (Ba(NO3)2), how many moles of barium nitrate do you have?
Answer: ??? moles Ba(NO3)2 (round to 5 sig figs)
Answer:
0.00021186 moles of barium nitrate
Explanation:
The given parameter is as follows;
The number of molecules of Barium nitrate Ba(NO₃)₂ = 1.2754 × 10²⁰ molecules
The number of molecule present per mole of Barium nitrate, is given by Avogadro's number, 6.02 × 10²³
1 mole of a substance contains 6.02 × 10²³ molecules
The umber of moles in a substance = (The number of molecules of the substance)/(The number of molecules per mole)
Therefore the number of moles of barium nitrate in 1.2754 × 10²⁰ molecules of barium nitrate = (1.2754 × 10²⁰)/(6.02 × 10²³) ≈ 0.00021186 moles (rounding to 5 significant figures)
The number of moles of barium nitrate present in 1.2754 × 10²⁰ molecules of barium nitrate ≈ 0.00021186 moles
A suspect could be exonerated if his/her hair was not found at a crime scene. True or False. If false why?
Answer:
False
Explanation:
Just because their hair is their doesn't mean they where their during that time period or their at all. It could have been brought in by someone else's clothes.
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We can determine the culprits by extracting the fingerprints and DNAs from the hair strand taken from the crime location. But if suspected one's hair is not found from the scene does not indicated that he or she was not involved in the crime. Hence, the statement is false.
What is forensic tests?Forensic laboratories tests samples from crime scenes. There are various advanced testing methods which helps to identify the culprits of a crime. For example the hair and fingerprints, clothes or any chemical materials, blood etc. obtained from the crime scene are tested to identify its owner.
Hair is made of proteins. From each hair strand we can extract a number of DNA molecules. Thus a hair strand obtained from a crime scene can be tested and can identify its owner.
However, sometimes there will be no evidences such as hair or blood in the crime location or sometime the may some samples which are not related the culprits.
Hence, it cannot be said that if there is no hair or any sample related with the suspected one from the crime scene, that they could be exonerated. Thus the statement is falls and he/she can be a culprit which can be proved in another way.
To find more about forensic tests, refer the link below:
https://brainly.com/question/9029550
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When we look at the periodic table of elements, the elements in a have the same number of valence electrons
Xenon-60 In order, what is the number of protons, electrons, and neutrons.
60,6,6
54,54,6
6,54,54
Answer:
I would say B?
54,54,6
Explanation:
6. This is the most commonly abused illegal drug in the United States
(5 Points)
Nicotine
Marijuana
Alcohol
Opioids
A 48.9 g piece of aluminum is dropped in a graduated cylinder partially filled with water. The original volume of water in the cylinder was 41.8 mL. The water rose to 54.4 mL when the aluminum was dropped in. What is the density of the aluminum?
Answer:
3.88g/mL
Explanation:
Density could be understood as the mass of a compound when it occupies 1mL.
To find the mass in 1mL we need to determine the volume that the piece occupies:
Based on Archimedes' principle, the volume of water displaced is equal to volume of the aluminium piece, that is:
54.4mL - 41.8mL = 12.6mL
As the piece has as mass 48.9g, the density is:
48.9g / 12.6mL =
3.88g/mLOrder the liquids from most dense to least dense: Water, Pancake Syrup/Maple Syrup, Cooking Oil, Milk, Dish Soap
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You walk 75 meters in 5 hours. What is your speed?
A.10 m/hr
B.5 m/hr
C.15 m/hr
D.12 m/hr
HELP!
When Iodine-131 emits a β particle (beta particle), what nuclide is produced? *
When Iodine-131 emits a β particle will produce Xe-131
Further explanationRadioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
alpha α particles ₂He⁴ beta β ₋₁e⁰ particles gamma particles ₀γ⁰ positron particles ₁e⁰ neutron ₀n¹So for reaction Iodine-131 :
[tex]\tt _{53}^{131}I\rightarrow _{-1}^0\beta +_{54}^{131}Xe[/tex]
Question, Answer, and Explanation are within the picture of files:
What is the mass of 2.3 moles of SnF4?
447.81830943999995. that's the mass
What is meaning of metabolism
Answer:
Metabolism is a combination of biochemical processes that your body uses to convert food into energy. These metabolic processes include breathing, eating and digesting food, the delivery of nutrients to your cells through the blood, the use of energy by your muscles, nerves, and cells, and finally the elimination of waste products from your body.
Hope this Helps!
Metabolism is the chemical processes that occur within a living organism in order to maintain life.
Hopes this helps luv! ο(=•ω＜=)ρ⌒☆
Is this equation completely balanced?
2C8H8 + 25O2 = 8CO2 + 18H2O
A. No, because the number of carbon, hydrogen & oxygen atoms on both sides of the equation are not equal.
B. No, because the number of oxygen atoms on both sides of the equation are not equal.
C. Yes, because all of the coefficients are in their lowest whole number ratio.
D. No, because the number of hydrogen atoms on both sides of the equation are not equal.
E. Yes, because the number of products is equal to the number of reactants.
A dog barks to alert his owner. What is the medium for the sound waves produced
by the dog barking? lesson 4.01
A. Air
B. ground
C. water
D. the ocean
Answer:
The Answer is ground or air
difference between calcium sulfide and calcium sulfate.
Answer: Calcium sulfide is a chemical compound having formula CaS. While Calcium sulfide is inorganic compound g fomlaCaSO4.
Explanation:
calcium sulfide is use in preparation of hydrogen sulfide, luminous pain and as a depilatory in cosmetics while calcium sulfate is used as desiccant. calcium sulfides is white material crystallizes in cubes like rock salt while calcium sulfate has three different crystalized forms known as hemihydrate (CaSO4⋅12H2O) , anhydrate (CaSO4) and as gypsum (CaSO4⋅2H2O). hope this explanation will be helpful for you
Which is classified as nonpolar covalent?
1) hydrogen and iodine
2) carbon and sulfur
3) hydrogen and chlorine
4) nitrogen and hydrogen
Answer:
3 i think...............
Answer:
3
Explanation:
What happens when the two negative ions are brought close together?
They attract each other to form ionic networks.
What is the formula for calculating time
Answer:
A
Explanation:
bc its right
The element in Group 14 Period 4 has how many neutrons and is it a metal, nonmetal, metalloid or noble gas.
Number of neutrons=41, and it is metalloid
Further explanationGroup 14⇒valence electron = 4(ns²np²)
Period 4⇒n=4
So electron configuration of the element :
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p² = 32 electron=atomic number
The element with atomic number 32, which is in period 4 and group 14 is Ge-Germanium
There are seven elements that can be classified as metalloids, namely boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), and polonium (Po).
While the mass number: 73
So the number of neutrons = mass number-atomic number
[tex]\tt 73-32=41[/tex]
Help!! In desperate need of help!!??
Answer:
MgO
Explanation:
How do plants take in oxygen?
Through photosynthesis
Through the stomata
By eating food
By sleeping
Through stomata....
hope it's helpful :)
When solid magnesium burns, it reacts with oxygen in the air to form a powder called magnesium oxide. A chemist performed this reaction in a lab and found that the mass of the magnesium oxide was greater than the mass of the magnesium. What is the reason behind this increase in mass?
Answer:
magnesium oxide is greater than the mass of the magnesium.
2. When the vapor pressure of water is 80 kpa the temperature of the
water is:
O 93 °C
O 103 °C
O 60°C
None of above
Answer:
103
Explanation:
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What makes up a film badge?
an electrolyte paste spread across a plastic sheet
a thin film of salts and other chemicals on clear acetate
layers of photographic film covered in black paper
a panel of photographic film exposed to the air
Answer:
Question:-What makes up a film badge?
Answer:-a panel of photographic film exposed to the air
Which of these is an example of a homogeneous mixture
A- Distilled water
B- A bar of pure gold
C- A solution of salt water
D- Carbon dioxide
Answer:
C- A solution of salt water
Explanation:
You cannot see the salt within the water, for it has already dissolved. The contents are uniformly distributed throughout the water's volume.
I hope this made sense! (^-^)
6. A serving of Cheez-Its releases 130 kcal (1 kcal = 4.18 kJ) when digested by your body. If this same amount of energy were transferred to 2.5 kg of water at 27°C, what would the final temperature be?
Answer:
78.8°C
Explanation:
Given parameters:
Amount of heat energy = 130kCal
Mass of the cheese = 2.5kg
Initial temperature = 27°C
Unknown:
Final temperature = ?
Solution:
To solve this problem, use the expression below;
H = m C (T₂ - T₁)
H is the amount of heat
m is the mass
C is the specific heat capacity of water = 4200J/kg°C
Now,
convert the amount of heat to kJ;
1kCal = 4.18KJ
130kCal = 130 x 4.18 = 543.4kJ
Insert the parameters and solve;
543.4 x 10³ = 2.5 x 4200 x (T₂ - 27 )
543.4 x 10³ = 10500 x (T₂ - 27 )
(T₂ - 27 ) = 51.75
T₂ = 51.75 + 27 = 78.8°C
The chemical formula for water is h2o. According to this formula what is the composition of a water molecule
Answer:
two hydrogen atoms and one oxygen atom
Explanation:
what happens to the radius of the atoms of an element as you go towards the right in a row of the periodic table ?
Answer:
It decreases
Explanation:
As one moves from left to right on the periodic table, the radius of atoms reduces due to the nuclear pull.
The size of an atom estimated by the atomic radius is taken as half of the internuclear distance between the two covalently bonded atoms of non-metallic elements. Across a period, atomic radius decreases progressively from left to right. This is due to the increasing nuclear charge without attendant increase in the number of electronic shell.Barbara completed an assignment for extra credit in science class. She used a pH meter to find the pH of different substances.
After she finished measuring the pHs, she created a diagram that showed the substances arranged in order from the most acidic to the most basic.
If Barbara added lemon juice—pH 2.2—to her investigation, where should it appear in her diagram?
A.
between milk and water
B.
to the left of cola
C.
between soap and bleach
D.
between water and blood
Answer:
if ur here for the coffee one its between cola and acid rain
Explanation:
ur mom
Which of the following would be a good choice of metal spoons to stir a
solution of lead(II) nitrate?
A. Silver
B. tin
C. nickel
D. Fe
Answer:
A. Silver
Explanation:
In order to answer this question accurately, we must have a good knowledge about the position of metals in the electrochemical series.
We must know that metals that are high above in the electrochemical series displace metals that are lower in the series from their aqueous solution. This means that tin, nickel and iron can all displace the lead from the solution of lead(II) nitrate.
However, silver is far less reactive than lead so it can not displace lead from its aqueous solution, hence the answer above.
