Calculate 1.4 + 15 + 7.15 +8.003 using the proper number of significant figures. 32 31.55 O 31.550 31.553 31.6​

Answer:

b 2,3,1

Explanation:

2 Al + 3 S ----> Al2S3

Answer:

Q8) True

Q9) First ionization energy

Q10) Metal oxides

Explanation:

A common property of group one elements (alkali metals) is their combination with water to form basic solutions. E.g 2K(s)+2H2O(l)→2KOH(aq)+H2​(g).

The distance of the outermost electron in the atom from the nucleus is inversely related to the first ionization energy. As the distance between the outermost electron and the nucleus in group 17 elements gets larger, the corresponding first ionization energies of elements in the group gets smaller.

Group 1 elements can combine with oxygen to give metal oxides. E.g  4K + O2 --> 2 K2O

Answer:

5 valence electrons

Explanation:

Answer:

5 electrons

Explanation:

Because atomic number of Nitrogen is 7 total 7 electrons are present 2 in first shell and 5 in valence shell

So these 5 electrons are known as valence electrons

Answer:

Well, there are a few reasons to be curious..

Being curious can: Keep your mind active instead of passive.

Keeps your mind observant on new ideas.

It also opens up new possibilities and keeps you creative.

You can have more excitement and mysteries in life!

Explanation:

Answer: I think you need to be curious because that is how we explore things. Many people find things interesting and if you don't inspect basically you will never learn to question right or wrong things.

Explanation:

Dimethylglyoxime is reacted with nickel ion solution. If it gives red precipitate then nickel ions are confirmed to be present.

Sodium hydroxide solution is been added to Copper Sulphate first in little and then in excess. A pale blue soluble precipitate is formed. This confirms presence of Cu²+.

CuSO4 + 2NaOH → Na2SO4 + Cu(OH)2

Answer:

The correct answer is 29 grams.

Explanation:

Based on the given question, the reaction will be,

CH3CH=CHCH3 + H2 ⇒ CH3CH2CH2CH3

The molecular weight of butene is 56 grams per mole, and the molecular weight of butane is 58 grams per mole.

Thus, it can be said that 56 grams of butene reacts with hydrogen gas and produces 58 grams of butane.

Therefore, 28 grams of butene when reacts with hydrogen gas to give,

= 58/56 * 28 = 29 grams of butane.

Hence, the mass of butane produced will be 29 grams.

Answer:

The amount of heat that is released is -925.2 cal

Explanation:

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

Sensible heat is the amount of heat that a body can receive or release without affecting its molecular structure, that is, it does not change the state (solid, liquid, gaseous).  In other words, sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state.

The equation that allows to calculate heat exchanges is:

Q = c * m * ΔT

Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.

In this case:

Replacing:

Q= 1 [tex]\frac{cal}{g*C}[/tex] *25.7 g* (-36 C)

Solving:

Q= -925.2 cal

The amount of heat that is released is -925.2 cal

Answer: yes

Explanation: I feed grasshoppers to frogs

Answer:

My hypothesis is that: If the electrolyte source is changed (potato, apple, lime, lemon), then the production of energy (measured in volts) using a lemon will produce the highest voltage because the acid content in the fruit or vegetable will produce electricity when in contact with the electrodes (both zinc and copper

Explanation:

The frequency of a radio wave was measured to be ( 3.1 x [tex]10^8[/tex] ) Hz . The  energy of the radio wave in kilojoules ( kJ ) is  20.5   x [tex]10^{-29}[/tex] kJ .

The radio waves are the types of the electromagnetic radiation .

Calculation ,

given frequency of radio wave ( v ) = 3.1 x [tex]10^8[/tex]  Hz

plank's constant ( h ) = 6.626 x [tex]10^{-34}[/tex] J.s ( given )

Formula used : E = hv

where h = plank's constant

v = frequency of radio wave

Now putting the value of all in equation ( i ) we get ,

E =  6.626 x [tex]10^{-34}[/tex] × 3.1 x [tex]10^8[/tex]  

E = 20.5   x [tex]10^{-29}[/tex] kJ

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Answer:

A big star collapsing creates a shock wave that can trigger fusion events in the star's outer shell, which is how I believe the process that took place in stars and supernovae to form the atoms that make up everything on Earth happened. Nucleosynthesis is the process by which these fusion processes produce new atomic nuclei. One of the primary sources of the universe's heavy elements is thought to be supernovae. It is possible to synthesize materials heavier than iron, such as uranium and gold, during a supernova because the star emits enormous amounts of energy and neutrons. All of these components are launched into space during the supernova explosion.

Answer:

the amount of mistakes?

Explanation:

Answer:

A

Explanation:

Bohr proposed that an electron is found only in specific circular paths, or orbits, around the nucleus

Answer:

We have to weigh 52.8 g of BaCl₂·2H₂O, add it to a 2.00 L flask and add water until reaching the final volume.

Explanation:

Describe the preparation of 2.00 L of 0.108 M BaCl₂ from BaCl₂·2H₂O. (244.3 g/mol).

Step 1: Calculate the moles of BaCl₂

We need to prepare 2.00 L of a solution that contains 0.108 moles of BaCl₂ per liter of solution.

2.00 L × 0.108 mol/L = 0.216 mol

Step 2: Calculate the moles of BaCl₂·2H₂O that contain 0.216 moles of BaCl₂

The molar ratio of BaCl₂·2H₂O to BaCl₂ is 1:1. The moles of BaCl₂·2H₂O required are 1/1 × 0.216 mol = 0.216 mol.

Step 3: Calculate the mass corresponding to 0.216 mol of BaCl₂·2H₂O

The molar mass of BaCl₂·2H₂O is 244.3 g/mol.

0.216 mol × 244.3 g/mol = 52.8 g

We have to weigh 52.8 g of BaCl₂·2H₂O, add it to a 2.00 L flask and add water until reaching the final volume.

Answer:

Elemental gold to have a Face-centered cubic structure.

Explanation:

From the information given:

Radius of gold = 144 pm

Its density = 19.32 g/cm³

Assuming the structure is a face-centered cubic structure, we can determine the density of the crystal by using the following:

[tex]a = \sqrt{8} r[/tex]

[tex]a = \sqrt{8} \times 144 pm[/tex]

a = 407 pm

In a unit cell, Volume (V) = a³

V = (407 pm)³

V = 6.74 × 10⁷ pm³

V = 6.74 × 10⁻²³ cm³

Recall that:

Net no. of an atom in an FCC unit cell = 4

Thus;

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

[tex]density = \dfrac{ 4 \ atm ( 196.97 \ g/mol) (\dfrac{1 \ mol }{6.022 \times 10^{23} \ atoms})}{6.74 \times 10^{-23} \ cm^3}[/tex]

density d = 19.41 g/cm³

Similarly; For a  body-centered cubic structure

[tex]r = \dfrac{\sqrt{3}}{4}a[/tex]

where;

r = 144

[tex]144 = \dfrac{\sqrt{3}}{4}a[/tex]

[tex]a = \dfrac{144 \times 4}{\sqrt{3}}[/tex]

a = 332.56 pm

In a unit cell, Volume V = a³

V = (332.56 pm)³

V = 3.68 × 10⁷ pm³

V  3.68 × 10⁻²³   cm³

Recall that:

Net no. of atoms in BCC cell = 2

∴

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

[tex]density = \dfrac{ 2 \ atm ( 196.97 \ g/mol) (\dfrac{1 \ mol }{6.022 \times 10^{23} \ atoms})}{3.68 \times 10^{-23} \ cm^3}[/tex]

density =17.78 g/cm³

From the two calculate densities, we will realize that the density in the face-centered cubic structure is closer to the given density.

This makes the elemental gold to have a Face-centered cubic structure.

The modern astronomer who provided insight into the physical phenomena of inertia through careful experiments was Galileo Galilei, who showed by empirical evidence the heliocentrism to left in the past the erroneous earthcentrism idea.

Galileo Galilei was one of the most important astronomers in history who showed through careful experimentation that the Earth orbit around the Sun, which is known as heliocentrism.

In conclusion, the modern astronomer who provided insight into the physical phenomena of inertia through careful experiments was Galileo Galilei, who showed by empirical evidence the heliocentrism to left in the past the erroneous earthcentrism idea.

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Answer:

53.96g

Explanation:

Given parameters:

Number of moles  = 1.52mole

Unknown:

Mass of the given mole  = ?

Solution:

The given element is chlorine;

        Mass of chlorine  = number of moles x molar mass

 Molar mass of chlorine  = 35.5g/mol

   So;

        Mass of chlorine  = 1.52 x 35.5 = 53.96g

The concentration of AB, in mol/dm³, after 6 minutes : 0.125

For first-order reaction :

[tex]\tt [A]=[A]oe^{-kt}\rightarrow t1/2=\dfrac{ln~2}{k}[/tex]

The half-life of the reaction is 2 minutes⇒t1/2=2 minutes

The concentration of AB, in mol dm, after 6 minutes ⇒ t=6 minutes

The rate constant (k) :

[tex]\tt k=\dfrac{ln~2}{t1/2}=\dfrac{0.693}{2}=0.3465[/tex]

The concentration after 6 minutes :

[tex]\tt [A]o=0.1~mol/100~cm^3=1~~mol/dm^3\\\\(A]=1\times e^{-0.3465\times 6}\\\\(A]=0.125[/tex]

Answer:

pollution cloud. im not really sure but hope this helps

Explanation:

The mass of the aluminum sample is 52 g.

The mass of the aluminum is determined by applying the principle of conservation of energy as shown below.

heat lost by aluminum = heat gained by water

m₁c₁Δθ₁ = m₂c₂Δθ₂

where;

m₁(0.897)(93.2 - 17.8) = (300)(4.186)(17.8 - 15)

m₁(0.897)(75.4) = (300)(4.186)(2.8)

67.634m₁ = 3516.24

m₁ = 3516.24/67.634

m₁ = 52 g

Thus, the mass of the aluminum sample is 52 g.

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Answer:

Mechanical Energy

Explanation:

Definition: Mechanical Energy The mechanical energy is

the sum of the kinetic and potential energies.

Answer:

b

Explanation:

Answer:

hot dog

Explanation:

Answer:

a

They form an ionic bond by exchanging two electrons.

Explanation:

Magnesium loses two electrons and oxygen gains these electrons so ionic bond is formed

The statement that best describes how magnesium (Mg) and oxygen (O) bond is, "they form an ionic bond by exchanging two electrons." This is further explained below.

Generally, bonding is the process of firmly connecting items together using adhesive, heat, pressure, or chemical bonding.

In conclusion, When magnesium (Mg) and oxygen (O) bond, they form an ionic bond by exchanging two electrons

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It would make the planet's tilt harder to change, which would mean a more stable climate, which “just means maybe ice ages wouldn't happen as often,” he told me.

The average weather throughout a region's long term, usually 30 years, is called the climate. More precisely, it is the mean and variability of meteorological variables over a period of time that can range from a few months to many millions of years. Temperature, humidity, air pressure, wind speed, and precipitation are a few of the meteorological parameters that are frequently observed.

Climate, in a larger sense, refers to the interactions between the atmosphere, hydrosphere, cryosphere, lithosphere, and biosphere as well as their status as parts of the climate system. Latitude/longitude, topography, altitude, land use, and the presence of surrounding water bodies and their currents all have an impact on a place's climate.

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Answer:

4

Explanation:

The Atomic number of beryllium is 4, which means that it has 4 protons.

Answer:

Observing. This is the most basic skill in science. ...

Communicating. It is important to be able to share our experiences. ...

Classifying. After making observations it is important to notice similarities, differences, and group objects according to a purpose. ...

Inferring. ...

Measuring. ...

Predicting.Explanation:

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