3 hazards that occur in teaching and learning of science
Which of the following did Antoine Lavoisier correctly characterize as an element? light silicone dioxide mercury
Answer: mercury
Explanation: I looked up the answer to your question.
Answer:
Mercury
Explanation:
I did this question and I got it right.
3z-1
= 162+2.642-2
4
Z=
the answer is z = 47.214
Answer:
z = 47.214
Hope this helped
What does the questions “how much?” and “how many?” have in common?
(02.02 MC)
How is Earth's surface most likely to change in a place that experiences strong sand storms?
Answer:
Mechanical weathering will cause wearing down of rocks.
Explanation:
All the other choices aren't suitable for a dry climate where sand storms occur.
what is the correct formula for the compound platinum (vi) flouride?
Answer: PtF6
Explanation: is one of seventeen known binary hexafluorides.
In most mirrors, the virtual image appears to come from behind the mirror. True False
Answer
False
Explanation:
How many grams of KF are in 2 liters of a 3.0 M solution of KF
Answer:
mass ( g ) = 348 g
Explanation:
First you know : M = mole / volume (L)
in question you have the M and V and the formula of SUBSTANCE ( KF )
first you get the number of mole from equation above
so 3 = no of mole / 2
no of mole = 3 × 2 = 6 moles
and the moles equation is no of moles = mass ( g ) / molecular weight ( g/mole )
so you have already calculate the moles and you can know the MW from the Question
Mw of KF = 39 + 19 = 58
so n = mass / MW
so 6 = mass / 58
mass ( g ) = 348 g
GOOD LUCK
How many senses does the human body have?
O A. 3
B. 5
Answer:
B
Explanation:
sight, hearing, smell, taste and touch
Answer:
Most easiest answer..
There are 5 senses in human body.☺️
Why is fusion not used to generate electrical power ?
Answer:
Fusion doesn't produce runway chain reactions the way fission can, so there's no need to worry about meltdowns.
what started the wildfires
Answer:
It is a typical fires that started out of a lightning strike, or people carelessly starting it, or accidentally, or even arson, that went un-noticed and got out of hand.
Answer:
Explanation:
Forest fires always start by one of two ways - naturally caused or human caused. Natural fires are generally started by lightning, with a very small percentage started by spontaneous combustion of dry fuel such as sawdust and leaves. On the other hand, human-caused fires can be due to any number of reasons.
You are given the reaction Cu + HNO3 Cu(NO3)2 + NO + H2O complete the final balanced equation based on half-reactions
The balanced equation based on half-reactions is 2Cu + 8HNO3 + 6H+ -> 2Cu(NO3)2 + 2NO + 4H2O.
How to determine the balanced equation based on half-reactionsTo complete the balanced equation for the given reaction Cu + HNO3 -> Cu(NO3)2 + NO + H2O using half-reactions, we need to break down the overall reaction into separate oxidation and reduction half-reactions.
1. Oxidation Half-Reaction:
Cu -> Cu2+ + 2e-
In this step, copper (Cu) is oxidized, losing two electrons to form copper(II) ions (Cu2+).
2. Reduction Half-Reaction:
HNO3 + 3H+ + 2e- -> NO + 2H2O
In this step, nitric acid (HNO3) is reduced, gaining two electrons to form nitric oxide (NO) and water (H2O).
Now, to balance the half-reactions, we need to make sure that the number of electrons gained in the reduction half-reaction is equal to the number of electrons lost in the oxidation half-reaction. In this case, we can achieve this by multiplying the oxidation half-reaction by two.
Balanced Half-Reactions:
Oxidation: 2Cu -> 2Cu2+ + 4e-
Reduction: HNO3 + 3H+ + 2e- -> NO + 2H2O
Finally, we can combine the balanced half-reactions to obtain the balanced equation for the overall reaction:
2Cu + 8HNO3 + 6H+ -> 2Cu(NO3)2 + 2NO + 4H2O
Therefore, the balanced equation based on half-reactions is 2Cu + 8HNO3 + 6H+ -> 2Cu(NO3)2 + 2NO + 4H2O.
Learn more about oxidation at https://brainly.com/question/25551544
#SPJ6
why is the international space station in orbit
Answer:
The ISS provides a location in the relative safety of low Earth orbit to test spacecraft systems that will be required for long-duration missions to the Moon and Mars.
Explanation:
how many number of electrons are in aluminium and nitrogen in their free state?
Answer:
MRCORRECT has answered the question
Explanation:
13 electrons
So... for the element of ALUMINUM, you already know that the atomic number tells you the number of electrons. That means there are 13 electrons in a aluminum atom. you can see there are two electrons in shell one, eight in shell two, and three in shell three.
7 electrons
So... for the element of NITROGEN, you already know that the atomic number tells you the number of electrons. That means there are 7 electrons in a nitrogen atom. Looking at the picture, you can see there are two electrons in shell one and five in shell two.
PLZZZ HELP CHEM!!!!!!! Easy points!!!!!
Answer:
H+
Explanation:
Answer:
OH-
Explanation:
An Arrhenius base is any species that increases the concentration of
OH
How many grams of H20 will be formed when 32.0 g H2 reacts with 16.0 g
O2? *
2H2 + O2 + 2H2O
9.00 g
16.0 g
18.0 g
32.0g
Answer:
18.0 g
Explanation:
M(H2) = 2.0 g/mol
32.0g * 1 mol/2 g= 16 mol H2
M(O2) = 32 g/mol
16.0 g * 1mol/32 g= 0.5 mol O2
2H2 + O2 ---> 2H2O
from reaction 2 mol 1 mol
given 16 mol 0.5 mol
We see that O2 is a limiting reactant.
2H2 + O2 +-------> 2H2O
from reaction 1 mol 2 mol
given 0.5 mol x mol
x =(0.5*2)/1= 1 mol H2O
M(H2O)= 18 g/mol
18 g/mol* 1 mol = 18 g H2O
Calculate the molar mass of ammonium chloride
Answer:
53.491 g/mol
Explanation:
Create the chemical compound and find each individual element's molar mass. Lastly, add them up.
Is the same reactant always the limiting reactant?
Grinding a seltzer tablet into powder increases the rate of reaction due to an increase of which factor?
Temperature
Surface area
Reactants
Concentration
Answer:
Surface area
Explanation:
The rate of a chemical reaction is increased when the surface area of a solid reactant is increased. This can be done by cutting the substance into small pieces, or by grinding it into a powder. If the surface area of a reactant is increased, it implies more particles are exposed to the other reactant.
When a seltzer tablet is ground into powder, the idea is to expose more of its surface to the other reactant. Since rate reaction depends on effective collision between reactants, more exposed particles implies a greater degree of collision between reactants and a faster rate of reaction.
Answer:
the answer is the second option got it right so do worry
Explanation:
hope this helps
what happens when light is not spread out
Answer:
Spreading out a wave over a larger area just causes the wave strength to weaken, but does not cause gaps to form. Therefore, if you look at photons as waves, spatial gaps never form in light as it travels through free space, no matter how dim it gets.Spreading out a wave over a larger area just causes the wave strength to weaken, but does not cause gaps to form. Therefore, if you look at photons as waves, spatial gaps never form in light as it travels through free space, no matter how dim it gets
Explanation:
1.
__________ are the most organized state of matter.
Solids
Liquids
Gases
2.
States of matter change when ________ is added or removed.
Plasma
Energy
3.
Which state of matter has the most movement of its particles?
Solid
Liquid
Gas
Solids are the most organized state of matter. States of matter change when energy is added or removed. Gas is the state of matter has the most movement of its particles.
What are the states of matter?The states of matter are the different forms of the matter in which it can exist. They are solids, liquids and gases. Solids are the states of matter in which molecules are very near to each other. They have fixed shape and volume. Liquids is the states of matter in which molecules are a little far from each other. They have different shape and fixed volume. Gas is the states of matter in which molecules are a very far from each other. They have different shape and different volume.
There are two more states of matter which are called as Plasma, Bose Einstein Condensate.
Plasma have highest energy and Bose Einstein Condensate have lowest energy.
Therefore, Solids are the most organized state of matter. States of matter change when energy is added or removed. Gas is the state of matter has the most movement of its particles.
To learn more about States of matter click:
https://brainly.com/question/29069107
#SPJ3
How many moles of H2 are needed to produce 18 moles NH3 in the reaction below?
N2 + 3 H2 —> 2 NH3
Answer:
27 moles of H₂
Explanation:
Equation of reaction:
N₂ + 3H₂ → 2NH₃
From the equation of reaction,
3 moles of H₂ is required to produce 2 moles of NH₃
3 moles H₂ = 2 moles of NH₃
X moles of H₂ = 18 moles of NH₃
X = (3 * 18) / 2
X = 27 moles of H₂
27 moles of H₂ is required to produce 18 moles of NH₃
Which of these conclusions is correct about P and Q in the diagram?
P represents the land and Q represents the ocean.
P represents the ocean and Q represents the land.
P represents the land and Q represents the atmosphere.
P represents the atmosphere and Q represents the ocean.
Answer:
P represents the atmosphere and Q represents the ocean.
Explanation:
Calculate the molarity of a nitric acid solution if 38 ml of the solution is neutralized by 16 ml of 0.25 M barium hydroxide solution. The balanced equation for the reaction is
Answer:
l
Explanation:
The element hydrogen has the highest specific heat of all elements. At room temperature, hydrogen's specific heat is 14.30 J/g •°C. If the temperature of a 340.0 g sample of hydrogen is to be raised by 30°C, how much energy will have to be added to the hydrogen?
Answer:
THE ENERGY NEEDED TO BE ADDED TO RAISE THE TEMPERATURE BY 30°C IS 145, 860 J
Explanation:
The energy needed can be calculated by using the heat formula, which is;
Heat = m c ΔT
m = mass of the hydrogen = 340 g
c = specific heat capacity of hydrogen at room temperature = 14.30 J/g°C
ΔT = change in temperature = 30°C
Heat =?
So therefore,
Heat = 340 * 14.30 * 30
Heat = 145860 J
The energy needed to be added to the hydrogen to bring the mass of 340 g to an increased temperature of 30°C is 145, 860 J or 145.86kJ
mutations that neither benefit nor harm the organism have (blank) effect on the organisms survival
Answer:
I would say that the mutation has no effect on the organism, as it doesn't help or harm it.
hope this helps :)
Explanation:
Answer:
its a neutral
Explanation:
i did the test
Do liquids have higher coefficients of expansion than solids do
Answer: yes they do.
Explanation:
I'm tryna get more points because my other account got blocked for the next 48 hours.
(Don't be mad at me please)
What is the value for AG at 500 Kif AH = 27 kJ/mol and AS = 0.09 kJ/(mol-K)?
Answer: -18
Explanation:
Facts
What is the value for ΔG at 500 K if ΔH= 27 kJ/mol and ΔS = 0.09 kJ/(mol⋅K)?
Explanation: ΔG= -18 kJ/mol
A 0.050L solution of Ba(OH)2 is neutralized by 0.072L of a 0.55 M HNO3 solution. What is the concentration of the Ba(OH)2 solution?
Answer:
0.396M
Explanation:
Step 1:
The balanced equation for the reaction. This is given below:
2HNO3 + Ba(OH)2 —> Ba(NO3)2 + 2H2O
From the balanced equation above,
The mole ratio of the acid (nA) = 2
The mole ratio of the base (nB) = 1
Step 2:
Data obtained from the question. This include the following:
Volume of base (Vb) = 0.05L
Concentration of base (Cb) =..?
Volume of acid (Va) = 0.072L
Concentration of acid = 0.55 M
Step 3:
Determination of the concentration of the base, Ba(OH)2.
The concentration of the base, Ba(OH)2 can be obtained as follow:
Cava /CbVb = nA/nB
0.55 x 0.072 / Cb x 0.05 = 2/1
Cross multiply to express in linear form
Cb x 0.05 x 2 = 0.55 x 0.072
Divide both side by 0.05 x 2
Cb = (0.55 x 0.072) / (0.05 x 2)
Cb = 0.396M
Therefore, the concentration of the base, Ba(OH)2 is 0.396M
In the graph above for the dissociation of a strong acid, why do the bars for H3O+ and A- have the same height as the bar for HA?
Answer:
The concentration of HA is the same as concentration of H3O+ and A- produced.
Explanation:
The dissociation equation is given below:
HA(aq) + H2O (l) —> H3O+(aq) + A-(aq)
From the reaction above, we can see that the acid is monoprotic acid i.e it has only 1 ionisable hydrogen atom.
Now, from the balanced equation, we can see that the acid produced equal concentration of H3O+ and A-.
This account for the reason why the bars for H3O+ and A- have the same height as the bar for HA.
