anyone know this? i’m having trouble...please help.
Why are poisons used less today than they were in the past? What factors influenced this change.
Answer:
Poisons are used less today than they were in the past because forensic scientists can easily detect many substances and toxins during an autopsy.
The main factor that influenced this change is advancements in forensic toxicology knowledge and technology.
good luck, i hope this helps :)
Explanation:
Today poisons are used less because forensic scientists now have much more equipment and have an easier time at identifying poisons like arsenic, which were not so easy to find in the past. The main factor influencing this change is the new technology and knowledge that was unavailable in the past.
The least polar bond is found in a molecule of hi hf hcl hbr
Answer:
HI is least polar
Explanation:
Balance Na + SO3 = Na2SO3
____ NaF + ____ Br2 à ____ NaBr + ____ F2
A. ---, 2, 2, ---
B. 2, ---, ---, 2
C. 2, ---, 2, ---
Answer:
2 NaF + Br2 --> 2NaBr + F2
Explanation:
Well first I notice that there are two flourines on the products side so we need to put a 2 of NaF. Now there are 2 sodiums on the products side so we have to put another two in front of NaBr.
2 NaF + Br2 --> 2NaBr + F2
how many molecules are in SO4
Answer:
there are 5 molecules in SO⁴
What is the SI unit of time?
A.
second
B.
minute
C.
hour
D. day
Answer:
option a. second
.............
When kci dissolved in ethanol what is the intermolecular attraction between k+ ions and ethanol molecules
Answer:
ion-dipole interaction
Explanation:
Ethanol is a polar molecule due to the presence of the polar O-H group in the molecule. This means that the molecule has a dipole moment.
The positive end of the dipole lies on hydrogen while the negative end of the dipole lies on oxygen.
When KCl is dissolved in ethanol, K^+ ions can interact with the negative end of the dipole in ethanol by ion-dipole interaction.
Help! Will give will give brainllest
1. An airplane flies 1431 miles in 2 hours 15 minutes. What is its average speed in miles per hour?
2. A train travels 76 miles in 1 7/12 hours. What is its average speed in miles per hour?
3. An airplane flies 1914 miles in 2 3/4 hours. What is its average speed in miles per hour?
4. A train travels 102 miles in 2 5/6 hours. What is its average speed in miles per hour?
5. Tracy runs 26.2 miles in 3 hours and 45 minutes. What is her average pace in minutes and seconds?
Answer:
1. 636miles/hour
2. 53.65milesper hour
3.696miles per hour
4.37.09mikes per hour
5. 6.99miles/hour
Explanation:
you first convert all the time into improper fractions
then work out speed which is got by dividing distance with time
Which best represents a physical change?
A. formation of a new substance
B. formation of a precipitate
C. condensation
D. bubbling
Answer:
The answer I would go with is A formation of a new substance.
Explanation:
This is because physical change includes changes of state. Some could be changing from a liquid to gas or solid to gas. B is not even an answer that should be considered because it doesn't fit into the category. C and D represents some of the examples of the process of physical change. Like boiling, bubbling, melting, or freezing. So the best would be A.
What is the molecular formula for C5H7 if its molar mass is 536 g/mol?
Answer:
(C5H7)8
Explanation:
It's empirical formula is given as; C5H7
Molar mass of carbon(C) = 12 g/mol
Molar mass of hydrogen(H) = 1 g/mol
We are told that it's molar mass is 536 g/mol.
To find the molecular formula;
Molecular formula = n × empirical formula
Thus;
n = 536/((12 × 5) + (1 × 7))
n = 8
Thus;
Molecular formula = (C5H7)8
How many atoms of oxygen are in a molecule
of
glucose (C6H1206)?
Be sure to use the correct place value.
Answer:
Um... 6
Explanation:
C6H12O6
The O is oxygen and the 6 is the exact number of atoms
I need help pls I don’t know this kne
Answer:
C. A one (1) is assumed when there is no coefficient
Explanation:
The following chemical equation is given in the attachment:
2H2 + O2 → 2H2O
In this reaction, Hydrogen (H2) and oxygen (O2) gases are the reactants and they combine to form H2O, which is the product. It is necessary that, in accordance to the law of conservation of matter, the same number of atoms of each elements on the reactant side equates that on the product side. When this happens, the equation is said to be BALANCED.
However, to balance an equation, COEFFICIENTS are used. In this equation above, coefficients 2 is used in front of both H2 and H2O but no coefficient is used in front of O2. This is because 1 mole of oxygen is on the reactant and product side respectively. However, one is assumed when no coefficient is written i.e. O2 means 1 mole of oxygen molecule.
Oddly shaped bones like your vertebrae and pelvis? a.irregular bones c. short bones b. flat bones d. long bones
Where does condensation occur?
lithosphere (rocky, crust of earth)
atmosphere (clouds)
hydrosphere (lakes and oceans)
biosphere (where the living things are)
what is an acid containg oxygen?
Explanation:
An oxyacid, oxoacid, or ternary acid is an acid that contains oxygen. Specifically, it is a compound that contains hydrogen, oxygen, and at least one other element, with at least one hydrogen atom bonded to oxygen that can dissociate to produce the H+ cation and the anion of the acid.
Answer:
oxyacid, oxoacid
Explanation:
An oxyacid, oxoacid, or ternary acid is an acid that contains oxygen. Specifically, it is a compound that contains hydrogen, oxygen, and at least one other element, with at least one hydrogen atom bonded to oxygen that can dissociate to produce the H+ cation and the anion of the acid.
Which characteristic is true of sexual reproduction but not of asexual reproduction?
Answer:
j one or more parents. that's the answer
Calculate the molarity for a solution containing 0.34 moles of NaNO3 dissolved in 0.5 liter of
water.
Answer:
0.68 mol/L
Explanation:
M=m/l
m is moles and l is liters
Since they gave us the values in the correct units, all we have to do it plug it in
M=0.34 mol/0.5 liters
M=0.68
How moles are in 45.7g of CH3?
first find the atomic weight of CH3 which would be
atomic weight: 12.011 (3×1.008) = 36.32 g/mol
then find the moles in the given mass
36.32 ÷ 45.7 = 0.794
I HOPE I'M NOT WRONG I HAVENT DONE CHEM IN SO LONG
Explain what a catalyst is and give an example of a transition as one.
Answer:
Catalyst, in chemistry, any substance that increases the rate of a reaction without itself being consumed.
...
Catalyst.
process catalyst
ammonia synthesis iron
sulfuric acid manufacture nitrogen(II) oxide, platinum
cracking of petroleum zeolites
Will mark brainiest!!!! Also I posted other questions
Answer:
Crash sensors measure how quickly a vehicle slows down in a frontal crash or accelerates to the side in a crash Some vehicles are equipped with a sensing system designed to detect the onset of a rollover crash Rollover crash sensors may be located in the ecu or at the center of the vehicle
The the Crash trip sensors in cars that send an electric signal to an ignitor The heat generated causes sodium azide to decompose into sodium and nitrogen gas which inflates the airbags
Explanation:
have a nice day
Explain why hydrocarbons are present in so many different compounds.
Answer:
Many hydrocarbons are found in plants, animals, and their fossils; other hydrocarbons have been prepared in the laboratory. We use hydrocarbons every day, mainly as fuels, such as natural gas, acetylene, propane, butane, and the principal components of gasoline, diesel fuel, and heating oil.
What do plants need in order to make food?
A. water, energy, oxygen
B.carbon dioxide, energy, oxygen
C.water, energy, carbon dioxide
D.water, oxygen, carbon dioxide
Answer:
Water, solar energy, carbon dioxide
Explanation:
If you are traveling at 40 miles per hour, how long will it take you to travel
80 miles?
Answer:
2hours
Explanation:
40miles=1hr
80miles=80÷40=2
2hours
Students are completing an investigation on types of heat transfer. For one part of the investigation, they place their hand on a cool window and feel the difference in thermal energy. When they are touching the glass, what type of heat transfer are they experiencing?
a .Conduction
b. Convection
c. Radiation
A typical tincture of iodine contains about 2.0% iodine by mass. Calculate
the mass of iodine in a 500. g tincture.
What special label do you have to use when naming ionic compounds with transition metals?
A) Roman Numerals
B) Greek Numerals
Naming Ionic compounds with transition metals requires the use of a roman numeral. The charge of the metal ion must be written in the name of the compound with a roman numeral. This is because transition metals can have more than one valence (or charge).
Some seawater is evaporated. The sea salt obtained is found
to be 86% sodium chloride. How much sodium chloride
could be obtained from 200 g of this salt?
Answer:
the answer is 172g
Explanation:
200 × 0.86 = 172g
A gas at 127 celsius and 10.0 L expands to 20.0 L. What is the new
temperature in kelvin? (You must convert to Kelvin before calculating
this problem
Answer:
T₂ = 800 K
Explanation:
Given that,
Initial temperature of the gas, T₁ = 127°C = 400 K
Initial volume, V₁ = 10 L
Final volume, V₂ = 20 L
We need to find the new temperature.
The volume of a gas is directly proportional to its Kelvin temperature.
Let T₂ is the new temperature. So,
[tex]\dfrac{V_1}{T_1}=\dfrac{V_2}{T_2}\\\\T_2=\dfrac{V_2T_1}{V_1}\\\\T_2=\dfrac{20\times 400}{10}\\\\T_2=800\ K[/tex]
So, the new temperature of the gas is 800 K.
Explain why is ortho nitrophenol more acidic than ortho methoxyphenol
Answer:
Ortho nitrophenol is more acidic than ortho-methoxyphenol.
Reason:
This is because the nitro-group is an electron-withdrawing group. In the case of ortho methoxyphenol; methoxy group is an electron-releasing group. Thus, it increases the electron density in the O−H bond and hence, the proton cannot be given out easily.
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