answer this question ​

Answer:

Average atomic mass of thallium = 204.4 amu.

Explanation:

Given data:

Abundance of thallium-203 = 30%

Abundance of thallium-205 = 70%

Average atomic mass = ?

Solution:

Average atomic mass of thallium = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

Average atomic mass of thallium = (30%×203)+(70%×205) /100

Average atomic mass of thallium =  6090 + 14350 / 100

Average atomic mass of thallium = 20440 / 100

Average atomic mass of thallium = 204.4 amu.

Answer:

Explanation:

2Ca    +    O₂   =    2CaO

80 g     32 g         112 g

given amount of Ca = 7.75 g

it will require oxygen =  32 x 7.75 / 80 = 3.1 g

but available oxygen = 2.44 so oxygen is the limiting reagent .

32g oxygen reacts with calcium to give 112 g of calcium oxide

2.44 gram of oxygen reacts with calcium to give 112 x 2.44 / 32 of CaO .

= 8.54 gram .

Theoretical yield of CaO = 8.54 gram.

Answer:

The metal is Copper

Explanation:

Matter is composed of atoms, which is the smallest indivisible particle of an element. The atom of an element consists of three subatomic particles namely: proton, electron and neutron etc.

The proton, which is the positively charged particle, is equal to the electron, which is the negatively charged particle. The proton number of the atom is the ATOMIC NUMBER of an element.

In the periodic table, the element with atomic number 29, which also means proton number 29 is Copper (Cu).

Answer:

c. the number of filled electrons shells increases

Answer:

the answer is c

Answer:

It is C

Explanation:

It is because Prokaryotic cells mostly don't have a nucleus.

Answer:

It is C.Eukaryotic cells have nuclei; prokaryotic cells do not

Explanation:

I just watched a video of it.

Answer:

D. Directly to The Right

Answer:

Tobacco use: The most preventable cause of cancer death

Explanation:

cancer might not be right

Answer:

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\[/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question

N = 1.505 × 10²³ Na atoms

We have

[tex]n = \frac{1.505 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{1}{4} \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

law of conservation of mass

Explanation:

Answer:

270.77 g of CO2.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

2C4H10 + 13O2 —> 8CO2 + 10H2O

Next, we shall determine the masses of C4H10 and O2 that reacted and the mass of CO2 produced from the balanced equation. This can be obtained as follow:

Molar mass of C4H10 = (12×4) + (10×1)

= 48 + 10 = 58 g/mol

Mass of C4H10 from the balanced equation = 2 × 58 = 116 g

Molar mass of O2 = 2 × 16 = 32 g/mol

Mass of O2 from the balanced equation = 13 × 32 = 416 g

Molar mass of CO2 = 12 + (16×2)

= 12 + 32 = 44 g/mol

Mass of CO2 from the balanced equation = 8 × 44 = 352 g

Summary:

From the balanced equation above,

116 g of C4H10 reacted with 416 g of O2 to produce 352 g of CO2.

Next, we shall determine the limiting reactant. This can be obtained as follow:

From the balanced equation above,

116 g of C4H10 reacted with 416 g of O2.

From the above, we can see that a higher mass of O2 i.e 416 g than what was given i.e 320 g his needed to react completely with 116 g of O2. Therefore, O2 is the limiting reactant and C4H10 is the excess reactant.

Finally, we shall determine the mass of CO2 produced from the reaction.

In this case, we shall use the limiting reactant because it will give the maximum yield of CO2.

The limiting reactant is O2 and the mass of CO2 produced can be obtained as follow:

From the balanced equation above,

416 g of O2 reacted to produce 352 g of CO2.

Therefore, 320 g of O2 will react to produce = (320 × 352)/416 = 270.77 g of CO2.

Thus, 270.77 g of CO2 were obtained from the reaction.

food moves through the mouth by muscle movement

Answer:

B. Each electron has its own "address."

Explanation:

This is the correct answer.

Good luck with the rest, and have a good day : )

Each electron has its own "address." Therefore, the correct option is option B among all the given options.

The elementary electric charge of the electron is a negative one, making it a subatomic particle. Due to their lack of components or substructure, electrons, which are part of the lepton particles family's first generation, are typically regarded to be elementary particles. The mass of an electron is roughly 1/1836 that of a proton.

The electron has a half-integer intrinsic rotational momentum that is represented in terms of the decreased Planck constant,, among its quantum mechanical features. The rule of exclusion developed by Pauli states that because electrons are fermions, no two of them may be in the same quantum state. Since they're capable of collide against other particles as well as can be bent like light, electrons, like all primary particles, display both wave and particle characteristics.  Each electron has its own "address."

Therefore, the correct option is option B.

To know more about quantization, here:

https://brainly.com/question/24256516

#SPJ2

Answer:

epithelium, muscle, connective tissue and nervous tissue.

Explanation:

Explanation:

Epithelial

Connective

Muscle

Nervous

Answer:

Trigonal planar

Explanation:

If we look at the carbon atom indicated I in the image, we will discover that it is a carbon atom that is bonded to a nitrogen atom via a double bond.

Recall that an sp2 hybridized carbon atom has a trigonal planar geometry. When a carbon atom is sp2 hybridized, it is in a trigonal planar geometry as we can clearly see from the image.

Answer:

hi :D

Explanation:

State the relationship between temperature and kinetic energy. The Kinetic Molecular Theory allows us to explain the existence of the three phases of matter: solid, liquid, and gas. In addition, it helps explain the physical characteristics of each phase and how phases change from one to another.

hope this helps

._.

...

Answer:

i think its alcohol and salt because they put salt on the ground to dissolve the snow so what I think is its alcohol and salt cuz they both look like they would evaporate pretty easy and alcohol evaporates really really easy so I think it's alcohol and salt because salt May absorb it or something I don't know but yeah

Answer: alcohol and iodide

Explanation:

Answer:

rock is the correct answer

Explanation:

Answer: here's the thing: rocks are minerals.Well, made out of them. so you can say that dolerite is a rock, but it is made out of minerals

Explanation:

Answer:

The release into the air of chemicals and particles can cause direct damage to the troposphere (air pollution); alter the composition and function of atmospheric layers (greenhouse effect) or other indirect damages (ozone layer depletion).

Explanation:

Answer:

a) first group

b) metals

c) K - potassium, Li - lithium

Explanation:

a) they are the alkali metals

b) they're alkali metals lol

c) just look at a periodic table :P

Answer: magnetic field

A field produced by a magnetic object that exerts a force on other magnetic materials or moving electrical charges is called a Magnetic field.

The magnetic subject is the region around a magnet in which the effect of magnetism is felt. We use the magnetic area as a device to describe how the magnetic force is shipped inside the area around and inside something magnetic in nature.

The magnetic area is extremely critical to maintaining lifestyles in the world. without it, we'd be exposed to excessive amounts of radiation from the solar, and our environment would be unfastened to leak into space.

Learn more about the magnetic fields here: https://brainly.com/question/7802337

#SPJ2

Answer:

alkali metals

Explanation:

alkali metals only have one valence electron, meaning they are extremely reactive. they are considered the most reactive on the periodic table.

Answer:

You would just put the definition and what it means im pretty sure

Explanation:

I hope this helps!!

Answer:

the atoms are rearranged

Explanation:

they are just in a diff order

The particle diagram represents a chemical change because the breaking of old chemical bonds and the formation of new chemical bonds occurs and a completely new substance is formed.

A chemical change is when a chemical substance is completely transformed into one or more different types of substances. Chemical changes occur through chemical reactions and result in substances with different and new chemical and physical properties.

Chemical changes are irreversible in nature and are also known as permanent changes. When chemical responses occur, the molecules are modified and joined by an energy change as new molecules are produced.

Examples of chemical changes: burning of coal, rusting of iron, digestion of food, adding vinegar to baking soda,  germination of seeds, ripening of fruits, cooking an egg, etc.

The given diagram is quite similar to the water formation reaction:

2H₂   + O₂  [tex]\longrightarrow[/tex] 2H₂ O

In which the bond between the hydrogen atoms and oxygen atoms is broken and the formation of the O-H bond, therefore, is a chemical change.

Learn more about chemical change, here:

brainly.com/question/23693316

#SPJ2

Answer:

Salt is effective as a preservative because it reduces the water activity of foods. .

Answer:

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\ [/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{2.16 \times {10}^{26} }{6.02 \times {10}^{23} } \\ = 358.80398671...[/tex]

We have the final answer as

Hope this helps you

Answer:

31.5 moles

Explanation:

Volume of H2O = 0.567 L

Number of mole of H2O =.?

Next, we shall convert 0.567 L to millilitres (mL). This can be obtained as follow:

1 L = 1000 mL

Therefore,

0.567 L = 0.567 L × 1000 mL / 1 L

0.567 L = 567 mL

Thus, 0.567 L is equivalent to 567 mL.

Next, we shall convert 567 mL to grams (g). This can be obtained as follow:

1 mL of H2O = 1 g

Therefore

567 mL of H2O = 567 g of H2O

Finally, we shall determine the number of mole in 567 g of H2O. This can be obtained as follow:

Mass of H2O = 567 g

Molar mass of H2O = (2×1) + 16

= 2 + 16 = 18 g/mol

Mole of H2O =?

Mole = mass /Molar mass

Mole of H2O = 567 /18

Mole of H2O = 31.5 moles