Answer:
Non-metal
Explanation:
A non-metal is a substance that possesses the following characteristics:
- It is brittle i.e can break easily
- It does not conduct heat and electricity
- It is not lustrous i.e does not shine when polished.
According to this question, LEEN was observing the physical properties of elements in order to classify them. He found that the first element was dull, brittle, and did not conduct heat. This makes it a NON-METAL.
Determine the number of shared and unshared electrons in the structure. shared (bonding) electrons: unshared (lone, nonbonding) electrons: Determine the number of shared and unshared pairs of electrons in the structure. shared (bonding) pairs of electrons: unshared (lone, nonbonding) pairs of electro
Answer:
Shared (bonding) electrons : 8
Unshared (lone, non-bonding) electrons : 16
Explanation:
The Lewis dot stricture of the molecule attached to this answer shows us all the valence electrons present in the molecule.
Altogether, we have a total number of 24 valence electrons in SO3.
There are eight electrons shared between atoms of elements, these are the bonding electrons.
There are sixteen electrons that are not shared between atoms of elements, These are the lone or non-bonding electrons.
Hence, there are four shared pairs of electrons and eight pairs of unshared electrons.
Somebody help me asap please giving brainliest
Answer:
fire > rocks > air
I need help with this pls help
Answer: true
Explanation:
Draw a line to connect the following terms to their definition.
An aqueous solution containing 6.06 g of lead(II) nitrate is added to an aqueous solution containing 6.58 g of potassium chloride. Enter the balanced chemical equation for this reaction. Be sure to include all physical states. balanced chemical equation: What is the limiting reactant
Answer:
Pb(NO₃)₂ is the limiting reactant.
The equation is: Pb(NO₃)₂ (aq) + 2KCl (aq) → PbCl₂ (s) ↓ + 2KNO₃ (aq)
Explanation:
We identify our reactants:
Pb(NO₃)₂ → Lead (II) nitrate
KCl → Potassium chloride
Our reaction is:
Pb(NO₃)₂ (aq) + 2KCl (aq) → PbCl₂ (s) ↓ + 2KNO₃ (aq)
1 mol of Lead (II) nitrate reacts to 2 moles of KCl, in order to produce 2 moles of potassium nitrate and 1 mol of slid Lead (II) chloride.
We determine the moles of the reactants:
6.06 g . 1mol /331.2 g = 0.0183 moles of Lead (II) nitrate
6.58 g . 1mol / 74.55g = 0.0882 moles of KCl
2 moles of KCl react to 1 mol of Pb(NO₃)₂
Then, 0.0882 moles of KCl may react to (0.0882 . 1) /2 = 0.0441 moles
We have 0.0183 moles of Pb(NO₃)₂ and we need 0.441 moles. Then, the
Pb(NO₃)₂ is our limiting reactant.
What is the pH of this solution?
Answer:
pH = 11.216.
Explanation:
Hello there!
In this case, according to the ionization of ammonia in aqueous solution:
[tex]NH_3+H_2O\rightleftharpoons NH_4^++OH^-[/tex]
We can set up its equilibrium expression in terms of x as the reaction extent equal to the concentration of each product at equilibrium:
[tex]Kb=\frac{[NH_4^+][OH^-]}{[NH_3]} \\\\1.80x10^{-5}=\frac{x*x}{0.150-x}[/tex]
However, since Kb<<<1 we can neglect the x on bottom and easily compute it via:
[tex]1.80x10^{-5}=\frac{x*x}{0.150}\\\\x=\sqrt{1.80x10^{-5}*0.150}=1.643x10^{-3}M[/tex]
Which is also:
[tex][OH^-]=1.643x10^{-3}M[/tex]
Thereafter we can compute the pOH first:
[tex]pOH=-log(1.643x10^{-3}M)\\\\pOH=2.784[/tex]
Finally, the pH turns out:
[tex]pH=14-2.784\\\\pH=11.216[/tex]
Regards!
1. What is the relationship between a DNA molecule, a gene and a protein?
Explanation:
for example, one gene will code for the protein insulin, which is important role in helping your body to control the amount of sugar in your blood. Genes are the basic unit of genetics. Human beings have 20,000 to 25,000 genes.
The element with the symbol Na
Select one
Cell
Metalloid
Non metal
Metal
Answer:
metal
Explanation:
it's a soft silvery metal
A gas occupies 5.0 cubic meters at a temperature of 600. K. If the temperature is lowered to 300. K at constant pressure, the new volume occupied by the gas will be:
Answer:
[tex]V_2=2.5m^3[/tex]
Explanation:
Hello!
In this case, according to the Charles' law as a directly proportional relationship between volume and temperature:
[tex]\frac{V_2}{T_2}=\frac{V_1}{T_1}[/tex]
Thus, in order to compute the final volume, V2, we obtain the following expression:
[tex]V_2=\frac{V_1T_2}{T_1}\\\\V_2=\frac{5m^3*300K}{600K}\\\\V_2=2.5m^3[/tex]
Best regards!
How many MOLECULES are in 5.0 grams of sodium chloride? (Use "molecules" as your unit...Enter as 9.9 x 10^99 molecules)
Answer:
[tex]\boxed {\boxed {\sf 5.2 *10^{22} \ molecules \ NaCl}}[/tex]
Explanation:
1. Convert grams to moles
First, convert grams to moles using the molar mass. This can be found on the Periodic Table.
Na: 22.9897693 g/molCl: 35.45 g/molSodium (Na) has an oxidation state of +1 and chlorine (Cl) has an oxidation state of -1, so they combine in a 1:1 ratio for a formula of NaCl. We can simply add their moles masses.
NaCl: 22.9897693 g/mol + 35.45 g/mol = 58.4397693 g/molUse this as a ratio.
[tex]\frac {58.4397693 \ g \ NaCl}{ 1 \ mol \ NaCl}[/tex]
Multiply by the given number of grams.
[tex]5.0 \ g \ NaCl *\frac {58.4397693 \ g \ NaCl}{ 1 \ mol \ NaCl}[/tex]
Flip the fraction so the grams of sodium chloride cancel.
[tex]5.0 \ g \ NaCl *\frac {1 \ mol \ NaCl}{ 58.4397693 \ g \ NaCl}[/tex]
[tex]5.0 *\frac {1 \ mol \ NaCl}{ 58.4397693 }=\frac {5.0 \ mol \ NaCl} { 58.4397693 } = 0.0855581749 \ mol \ NaCl[/tex]
2. Convert moles to molecules
We must use Avogadro's Number. This tells us the amount of particles (molecules, atoms, etc.) in 1 mole of a substance. In this case, it is molecules of sodium chloride.
[tex]\frac{6.022*10^{23} \ molecules \ NaCl} {1 \ mol \ NaCl}[/tex]
Multiply by the number of moles we calculated.
[tex]0.0855581749 \ mol \ NaCl*\frac{6.022*10^{23} \ molecules \ NaCl} {1 \ mol \ NaCl}[/tex]
The moles of sodium chloride cancel.
[tex]0.0855581749 *\frac{6.022*10^{23} \ molecules \ NaCl}{1}=5.15231329*10^{22} \ molecules \ NaCl[/tex]
The original measurement of grams has 2 (2 and 0) significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place. The 5 in the hundredth place tells us to round the 1 to a 2.
[tex]5.2 *10^{22} \ molecules \ NaCl[/tex]
Sound waves vibrate your eardrum, which moves bones in your middle
ear. The soundwaves then pass through a fluid in your inner ear, and on to
tiny hairs that send signals to the brain.
A. True
B. False
Answer: A. True
Explanation:
9. Which of the following is needed as a reactant for cellular
respiration?
A. Carbon dioxide
B. Oxygen
C. Water
D. Chlorophyll
oxygen is needed as a reactant for cellular respiration
What is cellular respiration ?
Cellular respiration can be defined as the process which occurs in every cells mainly mitochondria of plants and animals, it involve in the break down of sugars in the presence of oxygen and releases energy in the form of ATP.
The waste product of this process are carbon dioxide and water during exhalation process done by lungs, breathing and cellular respiration are related to each other.
At every step of cellular respiration energy is used in the form of ATP and carry out the normal function. It can aerobic and anaerobic respiration on the basis of use of oxygen.
For more details regarding cellular respiration, visit
brainly.com/question/14251313
#SPJ6
A sample of a gas at 25°C has a volume of 150 mL when its pressure is 0.947 atm. What will the temperature of the gas be at a pressure of 0.987 atm and changes to 144mL?
*please help*
Answer:
25°C
Explanation:
Combined Gas Law (P₁V₁)/T₁ = (P₂V₂)/T₂
(0.947 atm)(150 mL)/25°C = (0.987 atm)(144mL)/T₂
5.682 = 142.128/T₂
T₂ = 142.128/5.682
T₂ = 25.0137272756°C = 25°C
Balance the following equations.
Al4C3 + H2O → Al(OH)3 + CH4
NH3 + O2 → NO + H2O
Answer:
Al4C3 +12 H2O → 4Al(OH)3 + 3CH4
4NH3 + 5O2 → 4NO + 6H2O
Question 7 (1 point)
A sample of a gas has a pressure of 0.895 bar when the volume is 318 L. What is the
pressure of the gas when the volume is 125 L?
Answer:
2.28bar
Explanation: Boyle's law P1V1=P2V2 manipulate formula in favor of V2 the new formula should beP1V1/V2
0.895*318/125=2.2768 but to same sigfig it is 2.28
When a substance is a solid it has
A. Potential energy
B. Kinetic energy
C. Gravitational energy
D. Chemical energy
Answer:
potential energy
Explanation:
What is the concentration of a strong base solution (of an alkali metal) that has a pH of 11.39?
Answer:
[tex][OH^-]=2.455x10^{-3}M[/tex]
Explanation:
Hello there!
In this case, since a strong base produce OH ions in solution, it possible to first compute the pOH as shown below:
[tex]pH+pOH=14\\\\pOH=14-pH\\\\pOH=14-11.39\\\\pOH=2.61[/tex]
Thus, via the definition of the pOH we can compute the concentration of the strong base as follows:
[tex]pOH=-log([OH^-])[/tex]
Thus, solving for the concentration we obtain:
[tex][OH^-]=10^{-pOH}=10^{-2.61}[/tex]
[tex][OH^-]=2.455x10^{-3}M[/tex]
Best regards!
Which action is not an example of work?
A. pushing a box across the floor
B. picking up a box off the floor
C. holding a tray in the Cafeteria line
D. raising a barbell over your head
C. picking a tray in the cafeteria line
A chlorine concentration of 0.500 ppm is desired for water purification. What
mass of chlorine must be added to 2500 L of water to achieve this level?
Answer:
1.25 grams of chlorine.
Explanation:
Hello there!
In this case, since it is possible to define the parts per million of chlorine as the milligrams of chlorine per liters of water, in order to obtain the mass of chlorine in 2500 L, we proceed as follows:
[tex]ppm=\frac{mg}{L}\\\\mg=ppm*L[/tex]
In such a way, we plug in the given 0.500 ppm and 2500 L to obtain (in grams):
[tex]mg=0.500mg/L*2500L\\\\g=1250mg*\frac{1g}{1000mg}\\\\ g=1.25g[/tex]
Best regards!
Suppose you are titrating an acid solution with a base solution of known concentration. To calculate the concentration of the acid solution, use three steps.
1. Use the____of base____the endpoint and the known concentration of the base solution to find the_____of base used.
2. Use the_____to find the moles of acid from the moles of base.
3. Divide the moles of acid by the volume of_____the titration to find the concentration of acid.
Answer:
To calculate the concentration of the acid solution, use three steps.
1. Use the volume of base used at the endpoint and the known concentration of the base solution to find the moles of base used.
2. Use the stoichiometry to find the moles of acid from the moles of base.
3. Divide the moles of acid by the volume of acid used in the titration to find the concentration of acid.
Explanation:
Titration is the process used in volumetric analysis to determine the amount of a substance present in a given sample.
In any titration, a solution of known concentration known as the standard solution is used to react with a solution of of unknown concentration. The reacting volumes of the solutions are then used to calculate the unknown concentration of the second solution.
In acid-base neutralization reactions, an equivalence point/endpoint of the neutralization titration is obtained and is the point at which the moles of H+ is equal to the moles of OH- . An indicator is used to indicate the equivalence point during a titration by a color change observed in the indicator.
In order to calculate the concentration of an acid, we need to know accurately, use three steps:
1. Use the volume of base used at the endpoint and the known concentration of the base solution to find the moles of base used.
2. Use the stoichiometry of the reaction to find the moles of acid from the moles of base.
3. Divide the moles of acid by the volume of acid used in the titration to find the concentration of acid.
In order to calculate the concentration of a base, use three steps:
1. Use the volume of acid used at the endpoint and the known concentration of the acid solution to find the moles of acids used.
2. Use the stoichiometry of the reaction to find the moles of base from the moles of acid.
3. Divide the moles of base by the volume of base used in the titration to find the concentration of base.
An earthquake creates a type of wave that shakes the ground. If a large earthquake occurs in Greece, how can the waves be felt across the sea in Italy?
A.
Waves can be transformed into strong winds that travel across the sea.
B.
Waves do not travel through water, but they can crash the sea into land far away.
C.
Waves can cause a series of earthquakes around the world.
D.
Waves can travel through different media including solid land and water.
Which element's properties form the basis for all life?
Answer:
carbon
Explanation:
The properties of carbon forms the basis for all life. Explanation: The atoms of carbon are found in the molecules of all living species.
Which type of front is most likely moving through this area?
A. cold front
B. warm front
C. occluded front
D. stationary front
Answer:
Cold front
Explanation:
The number of moles of carbon dioxide which contain 8g of oxygen is
Answer:
0.25 mole of CO₂
Explanation:
We'll begin by calculating the mass of oxygen in 1 mole of carbon dioxide (CO₂). This is illustrated below:
Molecular formula of carbon dioxide
=> CO₂
Mass of oxygen in CO₂ = 2O
= 2 × 16
= 32 g
Thus, 1 mole of CO₂ contains 32 g of oxygen.
Finally, we shall determine the number of mole of CO₂ that contains 8 g of oxygen. This can be obtained as follow:
1 mole of CO₂ contains 32 g of oxygen.
Therefore, Xmol of CO₂ will contains 8 g of oxygen i.e
Xmol of CO₂ = 8/32
Xmol of CO₂ = 0.25 mole
Thus, 0.25 mole of CO₂ contains 8 g of oxygen.
A gas is at 39.2c and 4.50L. What is the temperature (oC) when the gas is expanded to 10L?
Answer:
420.7 degrees C
Explanation:
Use the formula V1/T1 = V2/T2 (Charles' Law) to find T2. Make sure to convert your temperatures to Kelvin by adding 273 to the Celsius temperature.
V1 = 4.50 L
V2 = 10 L
T1 = 39.2 C = 312.2 K
Solve V1/T1 = V2/T2 for T2 and you get T2 = V2T1/V1
T2 = (10 L)(312.2 K) / (4.50 L) = 693.8 K
You can subtract 273 to get the temperature back to Celsius.
T2 = 693.8 - 273 = 420.7 degrees C
What is the total number of oxygen atoms on the left-hand side of this chemical equation?
2 Caz(PO4),(s)+48i0,(s) +12C(s) - 4 Casio2(3)+P4($)+12CO(g)
Answer:
Is the answer eight atoms
The process of shedding an outgrown exoskeleton.
Answer:
Mouthing is the answer to your question
what is melting point
Answer:
it's a temperature where a solid will melt
In a circuit that has a total current of 4 amps with 4 lightbulbs wired in parallel, what is the current at each bulb?
Answer: 1 A for each lamps
Explanation: we assume lamps are similar and lamps have same resistance.
Then current is divided according Kirchhoff s law equally to all lamps.
If 85.6 grams of water are produced by the reaction then how many grams of calcium hydroxide did you start with?
Answer:
I think it would double it's self