Need help plz fast it’s science

Answer:

Detail is given below.

Explanation:

Calcium is alkaline earth metal. It has two valance electron. Thus calcium needs six more electron to complete the octet. Thus, its very easy for calcium to remove its two electron and get complete octet.

Electronic configuration of Ca:

Ca₂₀ = [Ar] 4s²

While,

Fluorine is halogen. It has seven valance electrons. It needed only one electron to complete the octet. When it combine with calcium , calcium loses two electrons thus two atom of fluorine combine with one atom of fluorine and stable compound calcium fluoride is formed.

Electronic configuration of F:

F₉  = [He] 2s² 2p⁵

Chemical equation:

Ca  + F₂     →     CaF₂

Answer:

From these two values, i.e. mass and volume, density of the copper cylinder can be calculated.

Formula of density is :

Density = Mass / volume.

Now we have mass: 53.76g and volume 6cm³

Density = 53.76 / 6

Density= 8.96 g/cm³

Answer:

mass number

Explanation:

When there is an element name followed by a dash and then a number, the number simply represents the mass number.

for example:

Oxygen- 18

18 represents the mass number of this particular isotope

Answer:

why do you not ask to your maam the answer

Answer:

To encourage readers to vary the design

Explanation:

Answer:

banging rocks together to see which make make a spark and create fire painting pictures is an example of art and sleeping in caves is survival

Answer: C.

Explanation: Alcohol floats on oil and water sinks in oil. Water, alcohol, and oil layer well because of their densities, but also because the oil layer does not dissolve in either liquid. The oil keeps the water and alcohol separated so that they do not dissolve in one another. ... Water sinks because it is more dense than oil.

Answer:

D

Explanation:

Meiosis is a series of steps that divides the cell's DNA  best explains the process of meiosis. Therefore, option D is correct.

A type of cell division in which each daughter cell receives half the DNA of the parent cell. In mammals, meiosis occurs during the formation of egg and sperm cells.

Due to the fact that cell division occurs twice during meiosis, a single starting cell can produce four gametes (eggs or sperm). Cells go through four stages during each round of division: prophase, metaphase, anaphase, and telophase.

Meiosis is also important for allowing genetic diversity and facilitating the repair of genetic defects via recombination.

Daughter cells are diploid after meiosis and have twice as much genetic material, which can be divided in an infinite number of ways.

Thus, option D is correct.

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Answer: This is because carbone dioxyde is composed of more than just an atom of carbon , it’s composed of 2 atoms of oxygen and one atom of carbon .

* I hope it was helpful , good luck :) *

Answer:

This shoes the soda lime defusing to limewater turning into germinating seeding which defuses back to limewater

Explanation:

The specific heat  capacity of the metal : 0.610 J/g° C  

The law of conservation of energy can be applied to heat changes, i.e. the heat received/absorbed is the same as the heat released  

Q abs = Q received  

Heat can be calculated using the formula:  

Q = mc∆T  

Q = heat, J  

m = mass, g  

c = specific heat, joules / g ° C  

∆T = temperature difference, ° C / K  

∆T = T(final temp) - T(initial temp)

mass of metal = 38 g

T initial metal = 92 °C

mass of water = 43 g

T final water = 30  °C

T initial water = 22°C

c water = 4.18 J/g° C  

[tex]\tt Q=m.c.\Delta T\\\\Q=43\times 4.18\times (30-22^oC)\\\\Q=1437.92~J[/tex]

Q water = Q metal

[tex]\tt 1437.92=38\times c\times (92-30)\\\\c=0.610~J/g^oC[/tex]

Answer:

Explanation:

This should be in physics.

d = 100 meters south

t = 13 seconds

v = d/t

v = 100 / 13

v = 7.69 m/s going south.

The point is that you have to specify the direction.

Answer:

C 14

Explanation:

Silicon atom has 14 protons. Given that a positive and a negative neutralize each other you need 14 electrons to neutralize the 14 protons.

Answer:

Br.

neutron = mass number - atomic number

youcan see the answer at the pic

The isotope that has 45 neutrons is B. 80,35Br.

The neutron can be obtained by subtracting the protons from the mass number. In the question, we have a proton that is numbered, 35 and a mass number of 80.

So, to get the neutron, we would subtract the protons from the mass number as follows;

80 - 35 = 45. The element that is described by this data is Bromine. Therefore, the correct option number is B. 80,35Br.

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Answer:

A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus and minus signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than are chemical names and structural formulae.

Explanation:

Have A Wonderful Day !!

Answer:

The correct options are;

1) Heat

2) Atoms

Explanation:

The heat required to raise a unit mass of a substance by one degree which is the specific heat capacity of the substance, is a quantity characteristic of a given substance and the amount of temperature change experienced by the substance when an amount of heat energy transferred to the substance is a function of the mass of the substance, which is a function of the number of atoms present in the substance.

So also, the total thermal energy that is stored by a substance, that causes a given amount of temperature change, is a function of the heat capacity of the substance.

Answer:

Option C

Explanation:

In Lewis dot structure the valence electrons are represented as dots around the symbol.

For example,

In hydrogen valence electron is only one it can be represented as,

H·

We know that in covalent bonding atoms share their electron to complete the octet. Thus, their Lewis dot structure would be represented as,

H:H

This is the Lewis dot structure of H₂.

In given atom X their are  2 valence electrons (3s²) thus its Lewis dot structure contain two dots around the symbol.

Option C is correct answer because it has only two dots which actually represent valence electrons.

Other options are incorrect because symbol X has more than two electrons/dots.

Answer:

Sulfur

Explanation:

Answer:

false

Explanation:

the energy causes the bonds to become looser

Answer: Ionic

Explanation:

Answer:

ionic

Explanation:

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]density = \frac{mass}{volume} \\ [/tex]

From the question

mass = 4 g

volume = 2 cm³

We have

[tex]density = \frac{4}{2} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

D = 2 g/cm³

Explanation:

Density = mass over volume

D= m/v

Step 1: Define

m= 4 grams

v= 2 cm³

Step 2: Substitute and Evaluate

D= 4 g/2 cm³

D= 2 g/cm³

Answer:

you shoudl ask this question more clearly?

Explanation:

Answer:

The 20th Element is Calcium (Ca).

The 20 Elements are:

Hydrogen

helium

lithium

berilium

boron

carbon

nitrogen

oxygen

flourine

neon

sodium

magnesium

aluminium

silicon

phosphorus

sulphur

chlorine

argon

potassium

calcium

The Answer fam is......... 1.82 × 10^4, Hence It's B)

Answer:

An ionic charge of 2-

Explanation:

The number of electrons is 8 and the number of protons is 2, subtract the two and the difference is the ionic charge. Hope this helps! :)

Answer:

This answer would be 2

Explanation:

The way that I have always done it is you put protons in tally marks (without crossing) over the top of the neutrons and mark them out one by one and whichever one that you have leftover that is your charge.

Hope this helps!

Answer:

C. convection and conduction

Explanation:

A sea breeze is a phenomenon that occurs during hot summer days when the sun transfers its heat to the earth surface by convection the land absorbs energy much easier than the seawater. As a result, the air above land will become warmer and as we know warmer air is lighter so this air will rise-up the air above the sea will now move from sea to the land to balance this air also there will be heat exchange between land air and the sea air by conduction and hence together they will create a phenomenon called a 'sea breeze'.

Answer:

Excited state of an electron is the state attained by an electron after it has absorbed energy and it moves further from the nucleus.

an electron is at higher energy when excited and at lower energy when at ground state.

an excited electron is less stable due to the decrease in the nuclear force of attraction and the grounded electron is more stable due to it's close distance to the nucleus.

An electron in excited state has its electron present in higher energy level while an electron in ground state is present in lower energy level.

Electrons present in an atom revolve in different orbits which are stationary states and are also called as energy levels. The energy levels are numbered as integers which are also called as principal quantum numbers.

Energy of the stationary state is given as E= -R

1/n² where R

is the Rydberg's constant. When an electron is excited, and it moves from lower to higher energy levels there is absorption of energy, while when it moves from higher energy level to lower energy level it radiates or gives out energy in the form of radiation.

They can also be defined as the distances between electron and nucleus of an atom . Electrons present in K energy level have least energy .Energy level diagrams are studied to understand nature of bonding , placement of electrons in orbits and and elemental behavior under certain conditions.

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Answer:

22572J

Explanation:

a) The following values have been given:

Mass of water = 180.0g

Initial temperature = 10°C

Final temperature = 40°C

molar heat capacity for water = 75.3J/Kmol

To calculate the specific heat capacity of water (c), we divide the molar heat capacity by molar mass of water (18g/mol)

That is; 75.3/18

= 4.183 Jg/K

b) The enthalpy change denoted by ∆H is the value we are trying to find.

c) To find enthalpy change (∆H), we use the formula:

∆H = m × c × ∆T

Where; m= mass

c= specific heat capacity

∆T= change in temperature =

(final temp - initial temp)

∆H = m × c × ∆T

∆H = 180 × 4.18 × (40-10)

∆H = 180 × 4.18 × 30

∆H = 22572J

You need to find the entropy of fusion in order to find this out.

Answer:

The penny now weighs 0.0025kg

Hope this helps please give me brainliest!

God bless!