Answer:
Li
Explanation:
It's on the periodic table.
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.
What volume of 12 M NaOH and 2 M NaOH should be mixed to get 2 litres of 9 M NaOH solution?
The volume of 12 M NaOH and 2 M NaOH should be mixed to get 2 litres of 9 M NaOH solution is 1.4 L and 0.6 L
What is Concentration ?
In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture.
Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration.
Amount of stuff = concentration x volume.
We can set up 2 equations:
V₁ = volume 12M NaOH.V₂ = volume 2M NaOH.(12×V₁) + (2×V₂) = 9×2 = 18
12V₁ + 2V₂ = 18 (1)
V₁ + V₂ = 2 (2)
From (2) we get:
V₁ = (2 − V₂)
Substituting V₁ back into (1) ⇒
12 (2−V₂) + 2V₂ = 18
24 − 12V₂ + 2V₂ = 18
10V₂ = 6
V₂ = 0.6L
From (2) we can say:
V₁ + 0.6 = 2
V₁ = 2 − 0.6 = 1.4L
Therefore, The volume of 12 M NaOH and 2 M NaOH should be mixed to get 2 litres of 9 M NaOH solution is 1.4 L and 0.6 L
Learn more about concentration here ;
https://brainly.com/question/19221273
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Subtract to find the temperature changes
for the water and the metal.
Answer:
???what metal????????????
What is the name of Ba(OH)2
Answer:
Barium Hydroxide
Explanation:
..........................
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
NO2 + H2O =
SO2 + H2O =
H2S + H2O=
SO2+ H2O=H2SO3
H2S+ H2O=H2SO4 +H2
NO2+ H2O= HNO3+NO
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
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.
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
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
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
1234567890123345678901234567890
Answer:
1234567890123345678901234567890
Explanation:
trick question....
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
CHEM FINAL PLEASE HELP
This is?
alkene
aromatic hydrocarbon
alkyne
alkane
Answer:
It is alkyne
Explanation:
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:
PLEASEE HELLLPPP mE WITH THE QUESTIONS I POSTE DIL MARK U THE BRAINLIEST I SWEAAARr
Answer:
PIEASE E first write question
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
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 mass of Na2SO4is needed to make 2.5 L of 2.0 Msolution? (Na = 23 g; S = 32 g; O = 16 g)
a.356 g
b.284 g
c.710 g
d.178 g
Answer:
mass (g) needed = 710.2 grams Na₂SO₄(s)
Explanation:
Needed is 2.5 Liters of 2.0M Na₂SO₄; formula wt Na₂SO₄ = 142.04g/mol.
mass (grams) of Na₂SO₄(s) = Molarity needed x Volume needed in Liters x Formula Wt of solute
mass (grams) of Na₂SO₄(s) = (2.5L)(2.0M)(142.04g/mol) = 710.2 grams Na₂SO₄(s)
Mixing: Transfer 710.4 grams Na₂SO₄ into mixing vessel and add water-solvent up to but not to exceed 2.5 Liters total volume. Mix until dissolved.
Gives 2.5 Liters of 2.0M Na₂SO₄(aq) solution.
Question 1 of 10
What does a low number on the pH scale say about a solution?
O A. The solution is an acid,
O B. The solution is changing.
O C. The solution is a base.
O D. The solution sg neutral.
What is the value of Keq for the reaction expressed in scientific notation? 1.6 ´ 10–5 6.2 ´ 10–4 6.2 ´ 104 1.6 ´ 105
The question is incomplete, the complete question is:
Consider the reaction:
[tex]2NOCl\rightleftharpoons 2NO+Cl_2[/tex]
At equilibrium, the concentrations are as follows. [NOCl] = 1.4 × 10–2 M [NO] = 1.2 × 10–3 M [Cl2] = 2.2 × 10–3 M What is the value of Keq for the reaction expressed in scientific notation?
A) 1.6 × 10–5
B) 6.2 × 10–4
C) 6.2 × 10+4
D) 1.6 × 10+5
Answer: The correct option is A) [tex]1.6\times 10^{-5}[/tex]
Explanation:
The equilibrium constant is defined as the ratio of the concentration of products to the concentration of reactants raised to the power of the stoichiometric coefficient of each. It is represented by the term [tex]K_{eq}[/tex]
For the given chemical equation:
[tex]2NOCl\rightleftharpoons 2NO+Cl_2[/tex]
The expression for equilibrium constant will be:
[tex]K_{eq}=\frac{[NO]^2}{[Cl_2][NOCl]^2}[/tex]
Given values:
[tex][NO]=1.2\times 10^{-3}M[/tex]
[tex][Cl_2]=2.2\times 10^{-3}M[/tex]
[tex][NOCl]=1.4\times 10^{-2}M[/tex]
Putting values in above expression, we get:
[tex]K_{eq}=\frac{(1.2\times 10^{-3})^2\times (2.2\times 10^{-3})}{(1.4\times 10^{-2})^2}\\\\K_{eq}=1.6\times 10^{-5}[/tex]
Hence, the correct option is A) [tex]1.6\times 10^{-5}[/tex]
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
Which method of separation would you use, if you want to collect.....A.Some sugar from a sugar solution? B.Rice grains, which have accidentally been mixed with flour? C.Some pure water from salty water?D.Some salt from salty water?E.Some clear water from muddy water?
Answer:
Explanation:
B.Rice grains, which have accidentally been mixed with flour
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
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.
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]
Which is TRUE about 'acidified' water acting on rocks?
Please give 1 answer.
A.
Peaty soil water does not cause weathering
B.
Limestone is eroded faster than basalt rock by this type of weathering
c.
It is an example of physical weathering
D.
Nearly neutral water will not weather rocks
KHP, the acid used in this experiment,
stands for potassium hydrogen
phosphorous.
True
False
Answer:
false
Explanation:
standard form is Potassium hydrogen phthalate
where was the first oil well drilled
Answer:
First oil well in the United States, built in 1859 by Edwin L. Drake, Titusville, Pennsylvania.
