PLease answer Physical or chemical change? Mothballs in a drawer disappear

How many neutrons and protons are there in the nuclei of the following atoms. a. Li-7 b. O-16 c. Th-232 d. Pu-239

ANEK [815]

Answer:

a.

P = 3 , N = 4

b.

P = 8 , N = 8

c.

P = 90 , N = 142

d.

P = 94 , N = 145

Explanation:

Mass number = Number of protons + Number of neutrons

Also,

Atomic number = Number of protons

Li - 7

Given, Mass number of Lithium = 7

For lithium, atomic number = 3

So,

Number of protons = 3

Number of neutrons = Mass number - Number of protons = 7 - 3 = 4

O - 16

Given, Mass number of oxygen = 16

For oxygen, atomic number = 8

So,

Number of protons = 8

Number of neutrons = Mass number - Number of protons = 16 - 8 = 8

Th - 232

Given, Mass number of Thorium = 232

For Thorium, atomic number = 90

So,

Number of protons = 90

Number of neutrons = Mass number - Number of protons = 232 - 90 = 142

Pu - 239

Given, Mass number of Plutonium = 239

For Plutonium, atomic number = 94

So,

Number of protons = 94

Number of neutrons = Mass number - Number of protons = 239 - 94 = 145

3 0

3 years ago

6) Which of the following does not fall in the biotic component of the ecosystem?

zlopas [31]

Answer:

6.grass

7.xylem

8.oval

9. poor growth of bones and teetn

4 0

3 years ago

Explain how atomic interactions determine a material to be transparent and opaque

mote1985 [20]

Answer:

The materials are opaque or crystalline from a client to the orientation and type of union between their atoms, forming two types of structures.

These two structures can be crystalline or amorphous.

In the case of being crystalline, these unions do not allow light to pass through the medium of the object or body of said compound, making it totally refract and giving the appearance of OPAQUE.

On the other hand, in those compounds that we call amorphous, the atoms are located in a different way that makes light pass through them, without absorbing or identifying any light beam, so they look transparent.

Explanation:

Example: A glass cup has an amorphous structure, while a porcelain or porcelain plate has a crystalline structure.

5 0

3 years ago

Consider the electrolysis of molten barium chloride (bacl2). write the half-reactions. include the states of each species.

aksik [14]

Molten barium chloride is separeted into two species :
BaCl₂(l) → Ba(l) + Cl₂(g),
but first ionic bonds in this salt are separeted because of heat:
BaCl₂(l) → Ba²⁺(l) + 2Cl⁻(l).

Reaction of reduction at cathode(-): Ba²⁺(l) + 2e⁻ → Ba(l).

Reaction of oxidation at anode(+): 2Cl⁻(l) → Cl₂(g) + 2e⁻.

The anode is positive and the cathode is negative.

7 0

3 years ago

A measure of the extra charges that are on an object is called

SashulF [63]

Charge is the measure of extra positive or negative particles an object has

8 0

4 years ago