Answer:
Radiation isn't beneficial to society .Radiation damages the cells that make up the human body. Low levels of radiation are not dangerous, but medium levels can lead to sickness, headaches, vomiting and a fever. High levels can kill you by causing damage to your internal organs. It's difficult to treat high radiation exposure.
Explanation:
Exposure to very high levels of radiation, such as being close to an atomic blast, can cause acute health effects such as skin burns and acute radiation syndrome (“radiation sickness"). It can also result in long-term health effects such as cancer and cardiovascular disease.
Radiation is both harmful and beneficial, but when we analyse it is found that harms overweight benefits. Radiation can be used as a form of energy (in nuclear plants), but an accident or malfunction in it can lead to death and injury of humans. Also, it is really difficult to dispose the used devices.
Será lançado na próxima quarta-feira, 1º de julho, em São Bernardo do Campo (SP), o primeiro ônibus brasileiro a hidrogênio. [...] O projeto Ônibus Brasileiro à Célula Combustível a Hidrogênio é o ponto de partida para o desenvolvimento de uma solução mais limpa para o transporte público urbano no Brasil. (Disponível em: Acesso em: 19 out. 2009.) Quanto aos processos químicos envolvidos na produção de energia elétrica em células de combustíveis a partir do oxigênio e do hidrogênio, é correto afirmar:
Subtract to find the temperature changes
for the water and the metal.
Answer:
???what metal????????????
KHP, the acid used in this experiment,
stands for potassium hydrogen
phosphorous.
True
False
Answer:
false
Explanation:
standard form is Potassium hydrogen phthalate
Nitrogen in plants and soil is changed into nitrogen compounds by _____ ?
Nitrogen Fixation because It's the process by which atmospheric nitrogen is converted either by a natural or an industrial means to form of nitrogen such as ammonia.
NO2 + H2O =
SO2 + H2O =
H2S + H2O=
SO2+ H2O=H2SO3
H2S+ H2O=H2SO4 +H2
NO2+ H2O= HNO3+NO
when water is added pH of the acidic solution
1 remain same
2 increases
3 decrease s
4 become zero
Answer:
the solution becomes less concentrated... meaning there is a decrease in acidity ...hence the pH slightly increases as lesser ph
means more acidity
Which two of the following changes of state involve solids?
Select two (2) answers
A. melting
B. boiling
C. freezing
D. evaporating
Answer:
Answer is A... Melting and freezing
please answer this as quickly as possible
Explanation:
I. Because an explosion is a very fast exothermic reaction
ll. it depends on the it's particle size
how much energy (in joules) is needed to change 45.0 grams of ice at -25.0 C to water at 49 C?
Explanation:
The heat required to convert 25 grams of -10 °C steam is 78360 J or 78.36 kJ.
3 Cu + 8HNO3 → 3 Cu(NO3)2 + 2 NO + 4 H2O
In the above equation, how many grams of water can be made when 15.9 moles of HNO3 are consumed?
Answer:
45673
Explanation:
(1) The solubility of Salt AB2(s) is 5mol/dm^3. (a) Obtain an expression for the solubility product of Salt AB2,in terms of s.
Answer:
See explanation
Explanation:
Let the equation of dissolution be;
AB2(s) ⇄A(aq) + 2S
Hence;
Ksp = [A] [2s]^2
Let the concentration of the species be s
Ksp= s × (2s)^2
Ksp= 4s^3
Since s= 5mol/dm^3
Ksp = 4(5mol/dm^3)^3
Ksp = 500 mol^2dm^-6
1234567890123345678901234567890
Answer:
1234567890123345678901234567890
Explanation:
trick question....
The absorption spectrum of sodium has a line at 589 nm. What is the energy of this line? (The speed of light in a vacuum is 3.00 x 10^8 m/s, and Planck's constant is 6.626 x 10^-34 Jos.)
A. 8.89 x 10^26 J
B. 5.09 x 10^14 J
C. 3.37 x 10^-19 J
D. 2.96 x 10^18 J
Answer:
C. 3.37 x 10^-19 J
Explanation:
The number of molecules in 17.9 g of CO is
Answer:
3.85 × 10²³ molecules CO
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableCompoundsMolesAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
Identify
[Given] 17.9 g CO
[Solve] molecules CO
Step 2: Identify Conversions
Avogadro's Number
[PT] Molar Mass of C: 12.01 g/mol
[PT] Molar Mass of O: 16.00 g/mol
Molar Mass of CO: 12.01 + 16.00 = 28.01 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 17.9 \ g \ CO(\frac{1 \ mol \ CO}{28.01 \ g \ CO})(\frac{6.022 \cdot 10^{23} \ molecules \ CO}{1 \ mol \ CO})[/tex][DA] Divide/Multiply [Cancel out units]: [tex]\displaystyle 3.8484 \cdot 10^{23} \ molecules \ CO[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
3.8484 × 10²³ molecules CO ≈ 3.85 × 10²³ molecules CO
A bird has flown 300 metres for 6 hours. What is the bird's speed? Formula for speed = d/t * 2 points
40 m/hr
50 m/s
50 m/h
50 m/min
Answer:
C
Explanation:
d=300
t=6hr
speed=?
speed=300/6
speed=50m/hr the important thing in this question is to get the right units
why is dilute tetraoxosulphate(VI) acid not suitable for preparing carbon monooxide
Answer: Because this does not dissolve in water - it forms a barrier on the surface of the unreacted CaCO3 which prevents any further reaction. A small volume of CO2 is produced , but this stops after a short time . Conclusion: H2SO4 cannot be used with CaCO3 to produce CO2 gas .
Explanation:
If 3.02 g of CuNO3 is dissolved in water to make a 0.560 M solution, what is the volume of the solution in milliliters?
Answer: The volume of the solution is 28.75 mL
Explanation:
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:
[tex]\text{Molarity of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (mL)}}[/tex] .....(1)
Given values:
Molarity of copper nitrate = 0.560 M
Given mass of copper nitrate = 3.02 g
Molar mass of copper nitrate = 187.56 g/mol
Putting values in equation 1, we get:
[tex]0.560=\frac{3.02\times 1000}{187.56\times \text{Volume of solution}}\\\\\text{Volume of solution}=\frac{3.02\times 1000}{187.56\times 0.560}=28.75mL[/tex]
Hence, the volume of the solution is 28.75 mL
Which of the following would DECREASE the rate of a reaction?
1. add a catalyst
2. increase the concentration
3. increase the volume
4. increase the pressure
Answer: increasing volume
Explanation: adding a catalyst would increase reaction time and increasing INCREASING concentration definently makes reaction time alot faster increasing pressure actually makes it more concentrated, so no it is not
Figure 1 (Use this figure to answer questions 6,7, and 8. Assume that the height at point
A and point C are the same)
С
B
As the car moves from point A, to point B, and finally to point C, the total energy of the car
decreases from point A to point B, then increases from point B to point
increases from point A to point B, then decreases from point B to point
O is lost between points B and C
stays the same, but is converted between potential and kinetic energy
Answer:
JWBVH
Explanation:
NWSBWHSBHS
A gas has a volume of 1000.0 mL at a temperature of 20.OK and a pressure
of 1.0 atm. What will be the new volume when the temperature is changed
to 40.0K and the pressure is changed to
0.5 atm?
Answer:
4000mL
Explanation:
Using the combined gas law equation;
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
V1 = initial volume (mL)
V2 = final volume (mL)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the information given in this question:
V1 = 1000mL
T1 = 20K
P1 = 1.0atm
V2 = ?
P2 = 0.5atm
T2 = 40K
Using P1V1/T1 = P2V2/T2
1 × 1000/20 = 0.5 × V2/40
1000/20 = 0.5V2/40
50 = 0.5V2/40
50 × 40 = 0.5V2
2000 = 0.5V2
V2 = 2000/0.5
V2 = 4000mL
How do the Carnivorous plants survive without soil?
Answer:
A simple answer: Carnivores don't eat plants only flesh. So they would not need soil. But it would be hard for Carnivores to get energy because they get energy indirectly from the animals (herbivores) that they eat. How do they get the energy from a herbivore you might ask. Herbivores eat only plants and that gives the herbivore the plant's energy; but if the herbivore gets eaten, it is indirectly transferred into the Carnivore. Hope this helped!!
Carnivore = only feeds on flesh
Herbivore = eats only plants
Omnivore = eats plants and animals/flesh
A boulder rests on a ledge 31.2 m above a lake. If it has 2.65 x 10 J of gravitational
potential energy relative to the lake surface, what is the mass of the boulder?
Answer:
This question is incomplete, the gravitational potential energy is 2.65 x 10^5 J
mass of the boulder = 866.7g
Explanation:
Potential energy (P.E) refers to the energy due to the position of a body. It can be calculated as follows:
P.E = m × g × h
Where;
m = mass of substance (g)
g = acceleration due to gravity (m/s²)
h = height (m)
According to the information provided in this question,
h = 31.2 m
g = 9.8m/s²
m = ?
P.E = 2.65 x 10^5 J
Using P.E = m × g × h
2.65 x 10^5 = m × 9.8 × 31.2
2.65 x 10^5 = 305.76m
265000 = 305.76m
m = 265000 ÷ 305.76
m = 866.69
mass of the boulder = 866.7g
calculate the oxidation number of the central atom of FeSO4 7H2O
Answer:
[tex]{ \tt{let \: the \: oxidation \: state \: be \: x}} \\ { \bf{x + sulphate \: ion+ water = overall \: charge}} \\ \\ \\ { \tt{x + ( - 2) + 0 = 0}} \\ \\ { \tt{x = + 2}} \\ { \tt{oxidation \: state = + 2}}[/tex]
State the name(s) of the sub-atomic particle(s) that have/has a positive charge. Answer with the name of the particle(s) only.
A. Neurons
B. Protons
C. Electrons
Answer:
protons because they have the most positive charge
Give an example of each of the following chemical changes.
(a) A photochemical reaction involving
(i) silver salt
(ii) water
(b) A reaction involving
(i) blue solution
(ii) formation of dirty green precipitate
(c) Two gases combine to form white solid.
(d) A reaction where colour change is noticed.
Answer:
Give an example of each of the following chemical changes.
(a) A photochemical reaction involving
(i) silver salt
(ii) water
(b) A reaction involving
(i) blue solution
(ii) formation of dirty green precipitate
(c) Two gases combine to form white solid.
(d) A reaction where colour change is noticed.
Explanation:
a) A photochemical reaction involving silver salt is used in black and white photography.
AgCl breaks down and converts into Ag during this photochemical reaction.
(ii) Photochemicalreaction involving water takes place in plants during the photosynthesis process.
Plants prepare food(carbohydrate) by using sunlight water and CO2 gas.
(b) A reaction involving
(i) blue solution:
For example reaction of copper sulfate solution with an iron nail.
When an iron nail is placed in CuSO4 blue color solution, then it changes to green color and reddish-brown solid deposits at the bottom of the container.
(ii) Reaction of ferrous sulfate with NaOH forms a dirty green precipitate of ferrous hydroxide.
(C) Two gases combine and form a white solid:
For example when HCl gas reacts with ammonia gas, then a white solid of ammonium chloride will be formed.
(d) A reaction where the color change is noticed.:
When an iron nail is placed in CuSO4 blue color solution, then it changes to green color and reddish-brown solid deposits at the bottom of the container.
Alpha particles cannot penetrate the skin. In which of the following circumstances could they still threaten human health?
A. If they travel into the human eye.
B. If they are inhaled or swallowed.
C. If they enter into the human ear.
D. If they are touched.
Answer:
B. If they are inhaled or swallowed.
What is meant by term valency? Explain it in terms of electrons donations and acceptance.
Answer:
Valency can be defined as a measure of the combining power of a chemical element with other atoms to form a molecule or chemical compound.
Explanation:
An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such determines or defines the structure of a chemical element.
Generally, atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.
In Chemistry, electrons can be defined as subatomic particles that are negatively charged and as such has a magnitude of -1.
Valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Valence electrons are used to determine whether an atom or group of elements found in a periodic table can bond with others. Thus, this property is typically used to determine the chemical properties of elements.
Valency can be defined as a measure of the combining power of a chemical element with other atoms to form a molecule or chemical compound.
Typically, valency is measured by the amount of hydrogen atoms that a chemical element can combine with or displace to form a molecule or chemical compound.
For example, Oxygen has a total number of eight (8) electrons while neon has total number of ten (10) electrons. Therefore, an atom of oxygen is able to gain (accept or receive) two (2) more electrons in order to have the same electron arrangements as the noble gas i.e an atom of neon with an atomic number of 10.
Question 9 of 10
Which functional group does the molecule below have?
Answer:
Hydroxyl
Explanation:
A P E X
An earthquake occurs at 8:15:35 PM, and a seismic station detects the P-
wave at 8:20:05 PM. What was the travel time for the P-wave to this
seismic station? *
- 3 minutes and 30 secs
-4 minutes and 30 secs
-5 minutes and 30 secs
-6 minutes and 30 secs
Answer:
5 minutes 35 seconds because an earthquake travels underground faster than on the surface
Why phenol is more acidic than alcohol?
Answer:
Phenol is more acidic than cyclohexanol and acyclic alcohols because the phenoxide ion is more stable than the alkoxide ion. ... But in a phenoxide ion, the negative charge is delocalized over the benzene ring. Phenoxide ion is therefore resonance stabilized.
Answer:
Phenol is more acidic than cyclohexanol and acyclic alcohols because the phenoxide ion is more stable than the alkoxide ion. ... But in a phenoxide ion, the negative charge is delocalized over the benzene ring. Phenoxide ion is therefore resonance stabilized.
Explanation:
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