How are a mole and a dozen similar?

Answer:

C

Explanation:

Answer:

The light microscope bends a beam of light at the specimen using a series of lenses to provide a clear image of the specimen to the observer.

Answer:

1.b

2.c

3.a

4.a

5.d

6.false

Answer:

telescope

Explanation:

i took the test

The telescope provide a means to explore the universe. There are different types of telescopes like reflecting, refracting, x-ray, gamma ray, etc. telescopes. The telescope used by the astronomer to study celestial objects with the shortest wavelengths is x-ray or gamma ray telescope.

An instrument which is used to view the distant objects is defined as the telescope. The higher the magnification of the telescope, the better will be the view. The lens in the front of the telescope is known as the objective lens.

There are two types of telescopes, they are refracting and reflecting telescopes. The refracting telescopes use lenses to focus the light whereas the reflecting telescopes use mirrors.

The X-ray and gamma ray telescopes collect light in the shorter wavelengths. X - ray telescopes help to study the sun, supernova and the other stars. Gamma ray telescope study black holes and pulsars.

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Answer:

1.4 g CaO

Explanation:

Given data:

Mass of calcium carbonate = 2.5 g

Mass of Cao remain in tube = ?

Solution:

Chemical equation:

CaCO₃    →     CaO + CO₂

Number of moles of CaO:

Number of moles = mass/molar mass

Number of moles = 2.5 g/ 100 g/mol

Number of moles = 0.025 mol

now we will compare the moles of CaO with CaCO₃.

                    CaCO₃        :          CaO

                        1              :             1

                    0.025         :         0.025

Mass of CaO:

Mass = number of moles × molar mass

Mass = 0.025 mol × 56 g/mol

Mass = 1.4 g

Answer:

1.4g CaO

Explanation:

Did the exam and got it right. Hope this helps

The mass of sodium chloride : 3.5 g

Given

Reaction :

2.5g of sodium sulphate + 4.5g of barium chloride ⇒ 3.5g of barium sulphate + sodium chloride

Required

The mass of sodium chloride

Solution

Conservation of mass applies to a closed system, where the masses before and after the reaction are the same

From the reaction :

mass of reactants = 2.5 g + 4.5 g = 7.0 g

mass of products = 3.5 g + mass of sodium chloride

mass of reactants = mass of products

7.0 g = 3.5 g + mass of sodium chloride

mass of sodium chloride = 7 g - 3.5 g =3.5 g

Answer:

Boyle's Law states that 'at constant temperature, the pressure of a fixed amount of gas varies inversely with the volume of the gas. Mountaineers have to carry oxygen cylinders with them to restore normal breathing because at high altitude the density of air is less.

Explanation:

I majored in Chemistry.

Answer:

It is balanced.

Explanation:

You have the same amount of atoms on both sides. 2 carbon and 4 oxygen.

Answer:

This shifts the star's spectral lines toward the red end of the spectrum. The greater the shift from the normal position of the lines, the faster the star is moving.

Answer:

the answer is c

Explanation:

My reasoning is that its most likely

Answer:

c or d it measures smallest to biggest and biggest to smallest

Answer:

your answer is a

Explanation:

Answer:

equal

Explanation:

According to the law of conservation of matter, the number of atoms before and after a chemical reaction should be equal, such that no atoms are, under normal circumstances, created or destroyed.

Answer:

Average atomic mass of the  vanadium = 50.9415 amu

Isotope (I) of vanadium' s abundance = 99.75 %= 0.9975

Atomic mass of Isotope (I) of vanadium ,m= 50.9440 amu

Isotope (II) of vanadium' s abundance =(100%- 99.75 %) = 0.25 % = 0.0025

Atomic mass of Isotope (II) of vanadium ,m' = ?

Average atomic mass of vanadium =

m × abundance of isotope(I) + m' × abundance of isotope (II)

50.9415 amu =50.9440 amu× 0.9975 + m' × 0.0025

m'= 49.944 amu

Explanation:

The abundance of the other isotope is 0.25% and the mass of the other isotope is 49.944 amu.

Natural abundance can be described as the abundance of isotopes of a chemical element naturally found on a planet. The relative atomic mass of these isotopes is the atomic weight of the element in the modern periodic table.

The abundance of an isotope can vary from planet to planet but remains relatively constant in time. The natural abundance of an isotope can be affected by the probability of its creation in nucleosynthesis and by the production of a given isotope as a daughter of the natural radioactive isotope.

Given, the average atomic mass of Vanadium = 50.9415 amu

The mass of one isotope = 50.9440 amu, relative abundance =99.75 %.

The relative abundance of the other isotope = 100 - 99.75 = 0.25 %

50.9415  = 50.9440 × 0.9975 + 0.0025 × M

Mass of other isotope = 49.944 amu

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Answer:

Mass = 234 g

Explanation:

Given data:

Mass of NaCl produced = ?

Moles of chlorine = 2.0 mol

Solution:

Chemical equation:

2Na + Cl₂    →     2NaCl

now we will compare the moles of NaCl with chlorine gas.

           Cl₂           :          NaCl

             1            :           2

            2.0         :         2/1×2.0 = 4.0 mol

Mass of NaCl;

Mass = number of moles × molar mass

Mass = 4.0 mol × 58.5 g/mol

Mass = 234 g

Explanation:

Gravitational potential energy

= mgh = (45kg)(9.81N/kg)(2m) = 882J.

The sled’s potential energy is 882 J.

The potential energy of the sled is calculated using the following formula as shown below;

P.E = mgh

Where;

P.E = 45 x 9.8 x 2

P.E = 882 J

Thus, the sled’s potential energy is 882 J.

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Answer:

Free chlorine involves the amount of chlorine that's able to sanitize contaminants, while combined chlorine refers to chlorine that has combined directly with the contaminants. Total chlorine is basically the sum of free chlorine and combined chlorine.

Answer:

yes

Explanation:

the definition for time is correct, the definition for speed is incorrect

Answer:

helium

The first ionization energy varies in a predictable way across the periodic table. The ionization energy decreases from top to bottom in groups, and increases from left to right across a period. Thus, helium has the largest first ionization energy, while francium has one of the lowest.

Explanation:

hope it helps, mark brainliest please

Answer:

Answer:

A molecule of Water consists of two atoms of hydrogen and one atom of oxygen.

The chemical formula for water is H2O .

Each hydrogen atom in a water molecule shares one valence electron(s) with the oxygen atom.

The chemical formula for carbon dioxide is CO2 .

The chemical formula CO represents the compound carbon monoxide.

Atoms or ions in compounds are held together by chemical bond.

Three types of chemical bonds are covalent, ionic, and metallic bonds

Answer:

the units of a formula mass are amu.

Answer:

chemical equation

Explanation:

Answer:

Water vapor has mostly disappeared at colder elevations and its effect on weather turbulence.

Explanation:

Answer:

B. Water vapor and its effect on weather turbulence has mostly disappeared at colder elevations.

Explanation:

Hope this helps

Answer:

D ( I am probably wrong)

Explanation:

Answer:

All atoms heavier than barium (Ba)

arium has completely filled 5d orbitals and 6s orbitals. After barium, the lanthanide elements occur, in which inner shell 4f-orbitals are filled. So all atoms heavier than Ba possess f-orbitals.

Explanation:

Answer:

Both r states of matter

Merry Christmas and a happy new year

Answer:

detail is given below.

Explanation:

The charged particles of nucleus are protons while neutrons are neutral having no charge.

We know that an atom consist of electrons, protons and neutrons. Neutrons and protons are present inside the nucleus while electrons are present out side the nucleus. Electron has a negative charge and is written as e⁻. The mass of electron is 9.10938356×10⁻³¹ Kg . While mass of proton and neutron is 1.672623×10⁻²⁷Kg and 1.674929×10⁻²⁷ Kg respectively.

Symbol of proton= P⁺  

Symbol of neutron= n⁰  

The number of electron or number of protons are called atomic number while mass number of an atom is sum of protons and neutrons.

one proton contribute 1 amu to the total weight. There are 20 protons and 20 neutrons in Ca thus its atomic mass is 40 amu.

While the atomic number is 20.

Answer:

Niche i think

Explanation:

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Answer:

hope this document helps! it's kinda hard to type out the explanation but ill try

Explanation:

divide the percenatge by the molar mass of the element.

(do this for both elements) \

find the lowest number and divide the results with it

now you have your empirical formula (with the rounded answers)

then find the molar mass of your empirical formula

divide the number given (267) by the molar mass to get a rounded number.

multiply that rounded answer to your empirical formula to get your empirical formula. :)