Answer:
FALSE
they're called transition metals
Answer:
false
Explanation:
The 38 elements in groups 3 through 12 of the periodic table are called "transition metals." As with all metals, the transition elements are both ductile and malleable, and conduct electricity and heat.
Indium-116 is radioactive and has a half life of 14.10 seconds. How long would it take a sample to decay from 7.70 mg to 900 µg.
Answer: 43.73 seconds
Explanation:
Half-life of indium = 14.10 sec
First we have to calculate the rate constant, we use the formula :
[tex]k=\frac{0.693}{t_\frac{1}{2}}[/tex]
[tex]k=\frac{0.693}{14.10}=0.0491sec^{-1}[/tex]
Now we have to calculate the age of the sample:
Expression for rate law for first order kinetics is given by:
[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]
where,
k = rate constant
t = age of sample = ?
a = initial amount of the reactant = 7.70 mg= [tex]7700\mug[/tex]
[tex](1mg=1000\mug[/tex]
a - x = amount left after decay process = [tex]900\mug[/tex]
Now put all the given values in above equation, we get
[tex]t=\frac{2.303}{0.0491}\log\frac{7700}{900}[/tex]
[tex]t=43.73sec[/tex]
Thus it would take 43.73 seconds sample to decay from 7.70 mg to 900 µg.
Two objects are described below.
Object 1: A skateboard with unbalanced forces
Object 2: A bicycle with balanced forces
Which statement is true about the objects?(2 points)
Both objects are moving.
Both objects are not moving.
Object 1 is moving, and Object 2 is not moving.
Object 1 is not moving, and Object
Answer:
Both objects are moving.
Explanation:
Object 1 is moving because the unbalanced force acting on the skateboard is causing it to either move slower or move faster. An example of this is when the skateboard is going down the hill. The unbalanced force is caused by the gravity which speeds up the skateboard.
Object 2 is also moving although it has a balance force; however, it is moving at a "constant speed." This is because the force of thrusting forward is being counteracted by a friction force of the same magnitude. Forces that are equal in magnitude and of opposing directions causing the speed to be constant. So, the bicycle is still moving.
12.5 mL of 0.280 M HNO3 and 5.0 mL of 0.920 M KOH are mixed. Is the resulting solution acidic, basic or neutral?
Answer:
The resulting solution is basic.
Explanation:
The reaction that takes place is:
HNO₃ + KOH → KNO₃ + H₂OFirst we calculate the added moles of HNO₃ and KOH:
HNO₃ ⇒ 12.5 mL * 0.280 M = 3.5 mmol HNO₃KOH ⇒ 5.0 mL * 0.920 M = 4.6 mmol KOHAs there are more KOH moles than HNO₃, the resulting solution is basic.
The resulting solution is basic.
• It is known that KOH is a base and HNO3 is an acid, so when they mix they undergo a neutralization reaction.
• The reaction between there will be,
HNO3 + KOH ⇔ KNO3 + H2O
Based on the given information,
• The volume of HNO3 is 12.5 ml and the molarity is 0.280 M, and the volume of KOH is 5 ml and the molarity is 0.920 M.
Now 1 mole of HNO3 completely reacts with 1 mole of KOH,
The millimoles of HNO3 is,
[tex]= Molarity * Volume (in ml)\\= 0.280 * 12.5\\= 3.5 mmol[/tex]
The millimoles of KOH is,
[tex]= Molarity * Volume (in ml)\\= 0.920 * 5.0\\= 4.6 mmol[/tex]
Now it can be seen that 3.5 millimoles of HNO3 completely reacts with 3.5 millimoles of KOH. Now we are left with 4.6-3.5 = 1.1 mmol of KOH.
Thus, KOH is in excess amount present in the solution, and as it is basic in nature, therefore, the resultant solution would be basic in nature.
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what types of air masses affect Florida
Answer:
The maritime tropical air mass keeps temperatures in Florida in the 80s and 90s in summer and in the 70s and 80s in winter. It can be pushed south by large continental polar and maritime polar air masses from the north and is affected by the reduced sunlight in winter.
Explanation:
There are different types of air masses based on the region from there they originates. Florida usually experience maritime and tropical air masses.
What is air masses?A huge body of air with a somewhat constant temperature and humidity is referred to as an air mass. Air mass source regions are the places where air masses originate.
For a sufficient amount of time, air will absorb the characteristics of the surface beneath it. The best source regions are those that are uniformly flat and composed. Siberia, central Canada, seas, and vast deserts are a few examples.
Tropical air masses are identified by a capital "T" for tropical. They originate in warm, tropical climates. A capital "A" for arctic is used to identify air masses that originate there. Dry air masses from the continental origin are those that originate over land.
Florida's northern and central regions experience a humid subtropical climate. The climate in South Florida is tropical. Hence tropical air masses are found in Florida.
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Why do you think elements have these repeating patterns and groups of similar elements ? Explain your reasoning as much as you can.
Answer:
The elements in the periodic table are arranged in order of increasing atomic number. All of these elements display several other trends and we can use the periodic law and table formation to predict their chemical, physical, and atomic properties. Understanding these trends is done by analyzing the elements electron configuration; all elements prefer an octet formation and will gain or lose electrons to form that stable configuration.
Please give me brilliant answer
Calculate the heat of reaction AH for the following reaction:
2 HCl(g) + F2(g) → 2 HF(g) + Cl2(9)
Answer:
can u give the bond energies
What happens in the redox reaction below? Select all that apply.
Na + F + NaF
A- Fluorine loses an electron.
B- Sodium loses an electron.
C- Sodium gains an electron.
D- Fluorine gains an electron.
E- Sodium is oxidized.
Answer:
B- Sodium loses an electron.
D- Fluorine gains an electron.
Sodium is oxidized.
Explanation:
The reaction equation is given as:
Na + F → NaF
In this reaction, Na is the reducing agent. It loses an electron and then becomes oxidized. By so doing, Na becomes isoelectronic with Neon.
Fluorine gains the electron and then becomes reduced. This makes fluorine also isoelectronic with Neon.
This separation of charges on the two species leads to an electrostatic attraction which forms the ionic bonds.
Please can someone help me on number 4 please it due today at 7:20pm please please help me will mark the brainiest please please help me please thank you
Answer:
I am the one who you just got a 100 points from from the 100 Point giveaway. I guess I gave away all my points except for one, so I need more points so I hope you don't mind if I am writing this, because you won't get another person to answer. Sorry!
Explanation:
3. Which has the largest atomic radius? *
O Calcium
0 Iron
Gallium
O Bromine
Answer:
the correct answer is calcium becuase it is over 200.
Explanation:
please mark brainlest and have a good day :)
how many neutrons does an atom of Vanadium contain
Answer: 28
Explanation:
20 POINTS + BRAINLIEST, HELP
Answer:
B
Explanation:
You add them all together if I'm correct. (I'm in middle school so don't get mad if its wrong lol)
Answer: 4) 2.5
Step-by-step explanation:
The ratio of line segments as per picture
5/x = 4.6/2.3
x = 2.5
Correct option is
4) 2.5
Explanation:JK ITS B.
Why did the hot water rise? Use faster, molecules, energy, density in your answer.
Answer:
Convection
Explanation:
Hot water will rise due to heat transfer by convection occurring in the heating system.
When a fluid is heated, the molecules will gain thermal energy. As the thermal energy of the liquid increases, the molecules will have heat which is average kinetic energy in the system. This causes them to be less denser and they rise in the cooking medium. As they rise, the colder part of the water sinks down to replace them in the pot. This exchange sets up convection cells in the heating medium.At which location are metamorphic rocks most likely to
form?
When rocks are subjected to high heat, high pressure, hot mineral-rich fluids, or, more typically, some combination of these variables, metamorphic rocks develop.
What are rocks?Rocks are defined as those formed from magma, a molten mixture of rock-forming minerals and typically volatiles such as gases and steam.
There are three types of rocks.
Igneous rock - They are defined as forms of rocks that occur when molten rock (rock that has been liquefied by extreme heat and pressure) cools to a solid condition.Sedimentary rock - They are defined as kinds of rock created by mineral or organic particle accumulation or deposition near the Earth's surface, followed by cementation.Metamorphic rock - They are defined as the rock developed throughout time as a result of many physical changes such as pressure, heat, and varied chemical activity. Metamorphism is the process through which existing rocks are transformed into new forms of rocks.Thus, when rocks are subjected to high heat, high pressure, hot mineral-rich fluids, or, more typically, some combination of these variables, metamorphic rocks develop.
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Write couple of paragraphs on "Role of Youths inreforming the society.
Answer:
Explanation:
They have the ability to learn and adapt to the environment. ... Our youth can bring social reform and improvement in society. We cannot make do without the youth of a country. Furthermore, the nation requires their participation to achieve the goals and help in taking the country towards progress
Please show work: A car travels at a rate of 65 miles per hour. If the car gets 33.5 miles to the gallon, how many hours can a car travel on 25.0 pounds of fuel? (density of fuel is 6.50 pounds/gallon)
Answer:
Explanation:
First divide 25.0 by 6.5 to get the amount of fuel you have.
How many mL of 0.650 M solution can be prepared by dissolving 15.0 g of copper(II) nitrate in
water?
Answer:
123.1L
Explanation:
Given parameters:
Molarity of Cu(NO₃)₂ = 0.650M
Mass of Cu(NO₃)₂ = 15g
Unknown:
Volume of Cu(NO₃)₂ = ?
Solution:
To solve this problem, we have to first find the number of moles of the given mass;
Number of moles of Cu(NO₃)₂ = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of Cu(NO₃)₂ = 63.5 + 2 (14 + 3(16)) = 187.5g/mol
Number of moles of Cu(NO₃)₂ = [tex]\frac{15}{187.5}[/tex] = 0.08 mol
Molarity is given as;
Molarity = [tex]\frac{number of moles }{volume}[/tex]
Volume = [tex]\frac{number of moles }{molarity }[/tex]
Insert the parameters and solve;
Volume = [tex]\frac{0.08}{0.65}[/tex] = 0.12L
Now mL;
1L = 1000mL
0.12L will give 1000 x 0.12 = 123.1L
which compound has covalent bonds? H2O, Li2O, Na2O, K2O
Answer:
H2O
Explanation:
H2O is just given as a covalent compound... Usually covalent bonds occur between 2 or more nonmetals.
Water or H₂O is a compound which has covalent bonds as there is slight difference in electronegativity of hydrogen and oxygen atoms.
What is a covalent bond?
Covalent bond is defined as a type of bond which is formed by the mutual sharing of electrons to form electron pairs between the two atoms.These electron pairs are called as bonding pairs or shared pair of electrons.
Due to the sharing of valence electrons , the atoms are able to achieve a stable electronic configuration . Covalent bonding involves many types of interactions like σ bonding,π bonding ,metal-to-metal bonding ,etc.
Sigma bonds are the strongest covalent bonds while the pi bonds are weaker covalent bonds .Covalent bonds are affected by electronegativities of the atoms present in the molecules.Compounds having covalent bonds have lower melting points as compared to those with ionic bonds.
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What is the ratio of ions needed to produce neutral potassium chloride?
A. One potassium ion to one chloride ion.
B. Two potassium ions to one chloride ion.
C. One potassium ion to two chloride ions.
D. Two potassium ions to three chloride ions.
Answer:
A
Explanation:
Why not
Answer:
A on edge 2021
Explanation:
Suppose a metal will eject electrons from its surface when struck by yellow light. What will happen if the surface is struck with ultraviolet light?
a. No electrons would be ejected.
b. Electrons would be ejected and they would have lower kinetic energy than those ejected by yellow light.
c. Electrons would be ejected and they would have the same kinetic energy by yellow light.
d. Electrons would be ejected and they would have greater kinetic energy than those ejected by yellow light.
Answer:
d. Electrons would be ejected and they would have greater kinetic energy than those ejected by yellow light.
Explanation:
A formula that describes the kinetic energy of an electron ejected when a surface is truck by light is:
Ephoton = KineticEnergyElectron + ΦAs you see, the higher the energy of the photon striking the surface, the higher the kinetic energy of the ejected electron.
Ultraviolet light has more energy than yellow light, so it would cause the ejected electron to have greater kinetic energy as well.
Consider the temperature versus time graph below. A graph of temperature versus time has time on the horizontal axis and temperature in degrees Celsius from negative 20 to 140 on the vertical axis. A line extends through the following points: 0, negative 10; 4, 0; 7, 140; 18, 120; 19, 125. At what temperature is the substance a heated gas? at 100°C below 0°C above 100°C between 0°C and 100°C
Above 100°Celsius is the temperature at which the substance is converted into a gas.
Different liquids have different boiling points at which they change from liquid to gaseous state. The boiling point of water is 100°Celsius means at 100°Celsius or above temperature, the water changes from liquid form into gas form or vapour form so we can conclude that at high temperature i.e. above 100°Celsius the substance is converted from liquid state to gaseous state.
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Assuming complete dissociation of the solute, how many grams of KNO3 must be added to 275 mL of water to produce a solution that freezes at −14.5 ∘C
Answer:
108.43 grams KNO₃
Explanation:
To solve this problem we use the formula:
ΔT = Kf * b * iWhere
ΔT is the temperature difference (14.5 K)Kf is the cryoscopic constant (1.86 K·m⁻¹)b is the molality of the solution (moles KNO₃ per kg of water)and i is the van't Hoff factor (2 for KNO₃)We solve for b:
14.5 K = 1.86 K·m⁻¹ * b * 2b = 3.90 mUsing the given volume of water and its density (aprx. 1 g/mL) we calculate the necessary moles of KNO₃:
275 mL water ≅ 275 g water275 g /1000 = 0.275 kgmoles KNO₃ = molality * kg water = 3.90 * 0.275moles KNO₃ = 1.0725 moles KNO₃Finally we convert KNO₃ moles to grams, using its molecular weight:
1.0725 moles KNO₃ * 101.103 g/mol = 108.43 grams KNO₃What is the molar ratio of Li to N2 in the given reaction?
6Li + N2 → 2Li3N
Answer:
6moles of Li : 1 mole of N₂
Explanation:
The reaction equation is given as:
6Li + N₂ → 2Li₃N
Mole ratio of Li to N₂;
From the balanced reaction equation:
6 moles of Li will react with 1 mole of N₂;
The mole ratio is:
6moles of Li : 1 mole of N₂
Write a decay equation for neon-19
Answer:
Neon
Mass Number Half-life Decay Mode
Electron Capture
Electron Capture with delayed Proton Emission
18 1.6670 seconds Electron Capture
19 17.22 seconds Electron Capture
Relation between glancing and angle of deviation
Answer:
the Glancing angle is the angle between the incident ray and plane mirror which is 90o in the given case. The angle between the direction of the incident ray and the reflected ray is the angle of deviation. Since the angle of deviation for a plane mirror is twice the glancing angle, the angle of deviation is 1800.
sodium chloride is made from sodium and chloride. would you expect the properties of sodium chloride to be simliar to sodium or cloride
Answer:
No
Its a chemical change so the characteristics or chemical properties always differs thereby the properties of sodium chloride isn't similar to sodium or chloride
If 11.2 g of naphthalene, C10H8, is dissolved in 107.8 g of chloroform, CHCl3, what is the molality of the solution?
a. 0.811m
b. 0.0941 m
c.12.4 m
d. 0.0875 m
e. 0.0969m
Answer: 0.811m
Explanation: Molarity is the moles of solute present per kg of solvent.
Molar mass of C10H8 = . 128.17 g/mol
No. of moles = given mass/molar mass
11.2g C10H8 = 11.2/128.17 g/mol C10H8
= 0.0874 mol C10H8
NOW 107.8g solvent (chloroform) contains 0.0879 molecules (naphthalene)
1000g '' will contain (0.0879/107.8 x 1000) mole solute
= 0.811 mole
Molarity of the solution is 0.811 m (option A)
Blood samples for research or medical tests sometimes have heparin added. Why is this done?
When a solid reaches its melting point, what happens? 1. melting 2. freezing. 3. vaporization 4. boiling
PLEASE HELP ME! CHEMISTRY!
reactants: calcium chloride + sodium bicarbonate
products: carbon dioxide + calcium carbonate + sodium chloride + dihydrogen monoxide
question; is this equation balanced? explain reason. if not balanced, how should it be balanced? what is the balanced equation?
Answer:
No it is not balanced
Explanation:
CaCl2 + 2NaHCO3 → CO2 + CaCO3 + H2O + 2NaCl
Hope this helps
What is the change in internal energy ΔU for a system that releases 241J of heat and does 1.20kJ of work on the surroundings. Answer may be in J or kJ.
Answer:
[tex]\Delta U=-1,441J[/tex]
Explanation:
Hello!
In this case, since the first law of thermodynamics explains how the heat added to the system and the work done by the system equals the change in the internal energy of the system, we can write:
[tex]\Delta U=Q-W[/tex]
Next, since the system releases 241 J of energy (negative on the previous equation) and does 1.20 kJ (1200 J) of work, the change in the internal energy turns out:
[tex]\Delta U=-241kJ-1,200kJ\\\\\Delta U=-1,441J[/tex]
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