Why are chromosomes not always visible?
a.
They are often very loosely coiled in strands of chromatin
c.
They lose pigment in sunlight
b.
They are wound very tightly
d.
They are often behind the nuclear envelope

Answer:

The correct option is;

CO₂

Explanation:

The given information are;

The number of molecules in the substance = 1.3 × 10²⁵

The mass of the substance = 968 g

Therefore, we have;

The number of molecules in one mole of a substance = 6.02 × 10²³

The number of moles present = (1.3 × 10²⁵)/(6.02 × 10²³) ≈ 21.595 moles

Therefore, 968 g = 21.595 moles

1 mole = 968/21.595 = 44.826 g

The mass of one mole of the substance = 44.826 g

Therefore the mass of one mole of the substance is closely related to the mass of one mole of CO₂ which is 44.01 g/mol.  

The correct option is CO₂

The number of molecules in one mole of a substance should be = 6.02 × 10²³

And,

The number of moles present is

= (1.3 × 10²⁵)/(6.02 × 10²³)

≈ 21.595 moles

Now

1 mole = 968/21.595 = 44.826 g

The mass of one mole of the substance = 44.826 g

So,  the mass of one mole of the substance is closely related to the mass of one mole of CO₂ i.e.  44.01 g/mol.  

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Answer:

Well what are the numbers but ik that it ius 5

Explanation:

Answer:

The answer is d

Explanation:

Answer:

genetics

hope this helps :)

Explanation:

Explanation:

The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Three widely used definitions of atomic radius are: Van der Waals radius, ionic radius, and covalent radius

Answer:

B

Explanation:

Mass number  = number of neutrons + number of protons

Atomic number is the number of protons in the nucleus.  

58Ni   : 58 is the number of neutrons + number of protons

atomic number of Ni is 28.  Thus,  58 -28 = 30 neutrons

57Co ;  57 is the number of neutrons + number of protons

number of Co is 27. Thus, 57 – 27  = 30 neutrons

Answer:

the answer is A)Oceans

Explanation:

Answer:

Explanation:

option A is correct

Ah yes.

The atomic radius is basically the distance between the nucleus of the atom and the outermost electron in the farthest orbital of the atom. The more bigger the atomic radius , the less powerful is the force that holds together the nucleus and its electrons.

Answer:

Oxgen- cannot be separated

Water - chemical change

Gold - cannot be separated

Carbon Dioxide - chemical change

Carbon​ - cannot be separated

Explanation:

A pure substance, which can either be an element or a compound, contains only one type of such element or compound. In opposition to a mixture, pure substances cannot be separated by physical means.

- Elements as a pure substance cannot be separated because it contains only one type of atom. However, compounds contain two or more types of atoms, and hence, can only be separated into its individual atoms via chemical means.

In this question, oxygen (O2), Gold (Au) and carbon (C) are all elements and hence cannot be separated. Carbon dioxide (CO2) and water (H2O) are compounds because they contain two different atoms respectively, hence, can be separated into individual atoms.

Answer:

the molecules and atoms start to vibrate faster so basically the object starts to expand because the space between atoms increases :)

Answer: argon

What must happen to a sulfur atom in order for it to have an electron arrangement similar to that of a noble gas? Answer: The noble gas closest to sulfur is argon. A sulfur atom gains two electrons to have an electron arrangement similar to that of argon.

Explanation:

Answer:

3.16×10⁹ pL

Explanation:

Given data:

Volume in mL = 3.16

Volume in picoliters = ?

Solution:

Picoliter and milliliters are units of volume. Milliliter is greater unit than picoliter.

1 mL = 10⁹ pL

Now we will convert the 3.16 mL into pL.

3.16 mL × 10⁹ pL/ 1 mL

3.16×10⁹ pL

Answer:

greece

Explanation:

aristole was particularly from stagria, greece. but most early philosophers are from greece

Answer:

Ag

Explanation:

atomic 33 because it what what sence

Answer: In the early 20th century, Wegener published a paper explaining his theory that the continental landmasses were “drifting” across the Earth, sometimes plowing through oceans and into each other.

Explanation:  He called this movement continental drift.

Answer:

Explanation:

Density is m/V. Also, 1 liter = 1000 [tex]cm^3[/tex]. So, we get 0.890/(5*1000) = [tex]1.78*10^{-4}[/tex] g/cm^3. You can convert this to kg/m^3 as well by multiplying it by 10. Depends which one you want.

The ratio of the mass in grams and volume in cubic meters gives the density. The density of 0.80 gm helium is 1.78 × 10 ⁻⁴ g/cm³.

Density is the amount or the number of entities that can be contained in an area. It is denoted by ρ and is calculated as,

Given,

Mass = 0.890 gm

Volume = 5000 cm³

ρ = Mass ÷ Volume

= 0.890 ÷ 5000

= 1.78 × 10 ⁻⁴ g/cm³

Therefore, 1.78 × 10 ⁻⁴ g/cm³ is the density of helium.

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Answer: 45

Explanation: it would be 45 bc if the value is 5 and over the number goes up and if it is lower than 5 it would stay the same.

Answer:

45 is the answer

Explanation:

Answer:4400

I went over this problem multiple times and I finally found the soultion

The concept of significant figures are mainly used by scientist and engineer to know the significance of digits in a measurement. Therefore, 4400L is the solution to the equation rounded to the correct number of significant figures.

Significant figures are the figures that indicate the degree of accuracy of a value. It tells about the precision of a value. It gives an idea about the digits that are necessary to indicate the experimental value.

Rules for counting significant figures are:

Number between 1 to 9 is always significant

Zeroes after a number has got no significance

Zeroes before a number has got no significance

Zeroes between number has got significance

4700 L - 281.4 =4400L

Therefore, 4400L is the solution to the equation rounded to the correct number of significant figures.

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Answer:

Answer Below

Explanation:

When you leave an apple on a table outside it will turn brown. This happens because when you cut an apple, you are exposing it's insides to the oxygen in the air. This causes the PPO (polyphenol oxidase) enzyme in the apple's flesh to oxidize the polyphenols, turning them into some other brown colored products. Hence, the color change.

Answer:

brown i can't explain because its a matter of the atoms in the apple mixing with the air and apple is made with nitrogen

Answer:

Granite Solid

Milk Liquid

Neon is gas

Wood Is solid

Paper is solid

Helium is Gas

Water is liquid

Air is Gas

Alcohol is liquid

Metal is solid

Nitrogen is gas

Juice is liquid

Oil is liquid

Water Vapor is Gas

Brick is Solid

Propane is Gas

Fabric is solid

Gasoline is Liquid

Explanation:

Hope Dis helped :D :3

Answer:

V = 21.2 cm³

Explanation:

Given data:

Diameter of block = 3.0 cm

Volume of block = ?

Solution:

Formula:

V = 2πr³

First of all we will calculate the radius from diameter.

r = d/2

r = 3.0 cm/2

r = 1.5cm

V = 2(22/7) (1.5cm)³

V = 2(3.14) (3.375cm³)

V = 21.2 cm³

The daughter isotope (a decay product): Polonium (Po)

Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,  

Radon-222 emits alpha α particles ₂He⁴  , so the atomic number decreases by 2, mass number decreases by 4

Reaction

[tex]\tt _{86}^{222}Rn\Rightarrow _{84}^{218}+_2^4He[/tex]

1. The mass number of the daughter isotope = 218

2 and 3. If we look at the periodic system, the element with atomic number 84 is Polonium (Po)

Answer:

D

Explanation:

Rusting is a chemical change that occurs due to oxygen.

Answer:

d i had this your welcome

Explanation:

solute is the substance being dissolved so that is the 2 tablespoons of lemonade and the 2 cups of water is the solvent.

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]