I need help with these two questions

I Need Help With These Two Questions

Answers

Answer 1

halogens have 7

allali have 2

noble gases have 8

K = 1

P = -3

Ra= 7

Cl = -1

N = 5

O = 6


Related Questions

What affects the pressure of an object? *

Answers

The pressure exerted on a surface by an object increases as the weight of the object increases or the surface area of contact decreases . Pressure depends on the amount of gas , the temperature, and the volume of the container .

TIME REMAINING
58:36
The electron configuration for Helium (He) is shown below.

1s2

Which diagram shows the correct distribution of electrons in the electron shells of a helium atom?

Answers

Answer:

'*:*'

Explanation:

I know this looks weird, but

'= electron

*:* equals the nucleus, so 2 protons and 2 neutrons

and then '=electron

N(p+) = 12, N(n0) = 14, N(e-) = 10

Answers

Answer:

Mg[tex]^+2[/tex]

Explanation:

Es el elemento que buscas.


Which iron pot has the least thermal energy?
A. A5 kg pot at 130°C
B. A 2 kg pot at 120°C
C. A 5kg pot at 25°C
D. A 2 kg pot at 25°C

Answers

Answer: D. A 2 kg pot at 25C.

Explanation:

What is the correct lewis dot structure for
24
12Mg 2+?

Answers

Answer:

Mg with 2 dots

Explanation:

Mg: as the valnce shell of Mg has 2 electrons only

presented by 2 dots

A car travels at 35.0 mi/hr. How far has it gone in 2455 seconds?

Answers

Answer:

The answer is 23.8 miles

Explanation:

The distance covered by an object given it's velocity and time taken can be found by using the formula

distance = velocity × time

From the question

velocity = 35.0 mi/hr

time = 2455 s = 0.68 hr

We have

distance = 35 × 0.68

We have the final answer as

23.8 miles

Hope this helps you

Radioactive isotope X has a half-life of 500,000 years. This isotope may be found in some types of volcanic rocks. A particular sample of volcanic rock taken from a layer that covered up some of the earliest known human-like footprints contains 0.125 mg of isotope X. The volcanic rock sample originally contained 8.00 mg of isotope X. How long ago were these footprints made. I need the equation. Thanks. please I am stuck on this question. PLEASE

Answers

Answer:

The age of the earliest known human-like footprints is approximately 3000000 years.

Explanation:

Decay of isotopes is represented by the following ordinary differential equation:

[tex]\frac{dm}{dt} = -\frac{m}{\tau}[/tex] (Eq. 1)

Where:

[tex]\frac{dm}{dt}[/tex] - First derivative of mass with respect to time, measured in miligrams per year.

[tex]m[/tex] - Current mass of the isotope, measured in miligrams.

[tex]\tau[/tex] - Time constant, measured in years.

Now we proceed to obtain the solution of the differential equation:

[tex]\int\limits {\frac{dm}{m} } = -\frac{1}{\tau}\int dt[/tex]

[tex]\ln m = -\frac{t}{\tau}+C[/tex]

[tex]m(t) = e^{-\frac{t}{\tau}+C }[/tex]

[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (Eq. 2)

Where:

[tex]m_{o}[/tex] - Initial mass of the isotope, measured in miligrams.

[tex]t[/tex] - Time, measured in years.

[tex]\tau[/tex] - Time constant, measured in years.

We proceed to clear time within the formula presented above:

[tex]\ln \frac{m(t)}{m_{o}} = -\frac{t}{\tau}[/tex]

[tex]t = -\tau \cdot \ln \frac{m(t)}{m_{o}}[/tex]

In addition, time constant can be found as a function of half-life:

[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (Eq. 3)

If we know that [tex]t_{1/2} = 500000\,yr[/tex], [tex]m_{o} = 8\,mg[/tex] and [tex]m(t) = 0.125\,mg[/tex], the age of the earliest known human-like footprints is:

[tex]\tau = \frac{500000\,yr}{\ln 2}[/tex]

[tex]\tau \approx 721347.520\,yr[/tex]

[tex]t = -(721347.520\,yr)\cdot \ln \left(\frac{0.125\,mg}{8\,mg} \right)[/tex]

[tex]t \approx 3000000\,yr[/tex]

The age of the earliest known human-like footprints is approximately 3000000 years.

A 5 kg block
is pulled across a table by a horizontal force of 4O N with a frictional force ot 8N pOsing the motion. Calculate the acceleration of the oject. 12 An ahia iddt​

Answers

Answer:

By Newton's 2nd law, m*a=sum_of_forces where m is the mass and a the acceleration. Here there are two forces in opposed directions.

Thus 5*a=40-8=32 therefore a=32/5=6.4m^s/2

There are several ways to model a compound. One type of model is shown. A central C attached to 3 C's by 1 line each, each of the 3 C's being attached to 3 H's by a 1 line each. The central C is also attached by 1 line to a C, which is attached to 2 H's and a C by a single line each. The C is attached by 2 lines to an O ad by 1 line to another O. The O with 1 line is attached by 1 line to an H. What is the chemical formula for the molecule modeled? CHO C4H11O2 C6H12O2 C6H9O

Answers

Answer:

C6H12O2

Explanation:

The first step in accurately deducing the structure/formula of the model is to count the number of carbon atoms, hydrogen atoms and oxygen atoms mentioned in the model. This gives the molecular formula of the compound.

Next, you look at there arrangement of atoms and bonds as stated in the model, this tells us the structure of the molecule and confirms the molecular formula initially deduced.

The structure of the compound is shown below.

Answer:

Your answer would be C6H12O2

Explanation: I hope I helped you :)

why does the uncertainty principle exist ?

Answers

Answer:

The uncertainty principle, proposed in 1927 by German physicist Werner Heisenberg, states that the more precisely a particle's position is measured, the less precisely its momentum can be known, and vice versa. ... They wanted to measure the polarization, or orientation, of the photon.

Can someone please help

Answers

Answer:

3

Explanation:

3 ampers (it says in the problem)

Draw a heating curve for a solid
Pls pls helppppp
I will mark u as Brainly and award 30 points !!!!

Answers

Answer:

Equation:

Q = m•C•ΔT

You can find a video under AboodyTV about heating curves and how to draw them.

How many bromine atoms are present in 38.7 g of CH2Br2

Answers

Number of Br atoms : 2.679 x 10²³

Further explanation

The mole is the number of particles contained in a substance

1 mol = 6.02.10²³

Moles can also be determined from the amount of substance mass and its molar mass

[tex]\tt mol=\dfrac{mass}{MW}[/tex]

Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements

mass of Br in CH₂Br₂

[tex]\tt mass~Br=\dfrac{2.Ar~Br}{MW~CH_2Br_2}\times mass~CH_2Br_2\\\\mass~Br=\dfrac{2.80}{174}\times 38.7=35.59~g[/tex]

mol of Br

[tex]\tt \dfrac{35.59}{80}=0.445[/tex]

number of atoms

[tex]\tt 0.445\times 6.02\times 10^{23}=\boxed{\bold{2.679\times 10^{23}}}[/tex]

HURRY I NEED HELP!! Please answer!!

Answers

Answer:

I'm confused on what u need us to answer

Beryllium
Symbol: Be
Atomic number: 4
Atomic mass: 9.012182 u

Lithium
Symbol: Li
Atomic number: 3
Atomic mass: 6.941 u

H2+ 02 H2O

how do you balence this ​

Answers

Answer:

As the number of atoms in the reactants side is equal to the number of atoms in the product side, the reaction is balanced

Two hydrogen molecules per oxygen molecule are produced because water (H2O) has a ratio of two hydrogen atoms to one oxygen atom. A decomposition reaction occurs when one reactant breaks down into two or more products. This can be represented by the general equation: AB → A + B.

H2O is the chemical formula of water. It means that each molecule of water is made up of two hydrogen atoms, indicated by the letter H, and a single oxygen atom, represented by the letter O. Water is chemical substance with no smell, taste or color.

Luciana explains to Eric how electricity flows in a circuit. Which sentences are a part of her explanation? Select all that apply.



A. Without a resistor, electricity cannot flow in a circuit.


B. Without a switch, electricity cannot flow in a circuit.


C. For electricity to flow in a circuit, the circuit must be complete.


D. An insulator such as plastic is needed for electricity to flow in a circuit.


E. A conductor is needed for electricity to flow in a circuit.

Answers

I’m pretty sure it c hope that helped

Answer:

E. A conductor is needed for electricity to flow in a circuit.

Explanation:

Electric current can flow without a resistor, as in short circuit.

A short circuit is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance.

Without a switch, electricity can flow in a circuit, switch is only used to close or open the circuit.

Thus, the only correct option is  E

E. A conductor is needed for electricity to flow in a circuit.

Please answer correctly !!!!!!!!!!!!!!!!! Will mark brainliest !!!!!!!!!!!!!!!! And explain please !!!!!!!!!!!!

Answers

Copper(II) chloride is a blue-green solid. When placed in water, the crystals turn bright green with a slight blue tinge in the water above the crystals. When stirred, the crystals dissolve and form a light blue solution

Hope this is your answer i wasn't able to see he full question so i am not sure

2. Explain how energy originates and is emitted from a star.

Answers

Answer:

Stars generate energy through nuclear fusion. Here's an easy explanation about how the process works. ... Stars spend most of their lives repetitively compressing two hydrogen atoms into a single helium atom – plus a lot of energy, which is released as light and heat.

19. Who was the first female astronomer

A.Aristotle
B.En Hedu’Anna
C.Archimedes
D.Plato

Answers

Answer: A.En Hedu'Anna

Answer:

En Hedu’Anna!

Explanation:

help quick please?????

Answers

Answer:

the core

Explanation:

Answer:

3rd option, the core.

Explanation:

How many molecules are in 937 g of calcium acetate?

Answers

Answer:

158.17

Explanation:

divide the given mass by the molar mass

How much energy is required to heat 0.24 KG lutetium from 296.2K to 373.5 K? The specific heat for lutetium is 0.154 J/g-K

Answers

Answer:D. 2857 joules

Explanation:

Not going to lie I guessed but got it right

According to specific heat capacity, 3596.208 joules of energy is required to heat 0.24 kg of lutetium from 296.2 K to 373.5 K.

What is specific heat capacity?

Specific heat capacity is defined as the amount of energy required to raise the temperature of one gram of substance by one degree Celsius. It has units of calories or joules per gram per degree Celsius.

It varies with temperature and is different for each state of matter. Water in the liquid form has the highest specific heat capacity among all common substances .Specific heat capacity of a substance is infinite as it undergoes phase transition ,it is highest for gases and can rise if the gas is allowed to expand.

It is given by the formula ,

Q=mcΔT

Substitution in above formula gives, q= 0.24×154×97.3=3596.208 Joules.

Thus, 3596.208 joules of energy is required to heat 0.24 kg of lutetium from 296.2 K to 373.5 K.

Learn more about specific heat capacity,here:

https://brainly.com/question/1747943

#SPJ2

What two elements fill their last electron in the 5s sublevel?

Answers

Answer:Rubidium and Strontium

Explanation:

The capability of a substance to be stretched into thin wires without breaking is known as —
A malleability
B conductivity
C luster
D ductility

Answers

the answer is ductility

Answer:

The answer is D, ductility

Explanation:

The definition of ductile is "(of a metal) able to be drawn out into a thin wire."

Does Magnesium or Carbon have similar properties to Beryllium ? Which one ?

Answers

Answer:

Yes, Magnesium

Magnesium has similar properties

Is wax ionic or covalent? why?

Answers

Answer:

Candle wax will melt to a liquid and burn as a gas. Only covalent compounds can be liquid or gas!

Explanation:

Question: Is Wax Ionic Or Covalent? - Ceramicsexpandusceramics.com

In the given question, wax is a covalent compound because it is composed of nonmetal atoms that share electrons to create covalent bonds.

Covalent compounds are formed when two or more nonmetal atoms share electrons in order to achieve a stable electron configuration.

Wax is made up of long-chain hydrocarbons, which are molecules that contain only carbon and hydrogen atoms. The carbon and hydrogen atoms in these molecules share electrons to form covalent bonds.Ionic compounds, on the other hand, are formed when a metal and a nonmetal react.

Therefore, wax is a covalent compound because it is made up of non-metal atoms sharing electrons to form covalent bonds.

Learn more about covalent compounds here:

https://brainly.com/question/11632372

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Which two models can be classified as elements

Answers

Answer:

First One And Third Pls Mark Brainlest

Explanation:

Which statement is the best description of a chemical bond?
O A. A chemical bond connects 2 different molecules.
B. A chemical bond holds atoms together.
C. A chemical bond turns molecules into atoms.
D. A chemical bond identifies atoms in a molecule.

Answers

The answer Is B;A chemical bond holds atoms together.

HELP PLEASE!!!
chemistry question

Answers

Answer:

Its going to be D) In sigma bonds the electrons are in the space between the joined atoms and pi bonds above and below the joined atoms

The answer is D
The electrons are in the space above and below the joined atoms.


Which of the following pairs of elements belong to the same period?

Answers

Answer:

He and Ar

Explanation:

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