1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
astra-53 [7]
3 years ago
15

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

Chemistry
1 answer:
ANEK [815]3 years ago
3 0

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

<u>Li - 7</u>

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

<u>O - 16</u>

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

<u>Th - 232</u>

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

<u>Pu - 239</u>

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

You might be interested in
If 5.0 liters of carbon dioxide gas are produced by the reaction below at STP, how many liters of oxygen gas were used in the re
svp [43]
At STP

1L O₂ → 2L CO₂
xL O₂ → 5.0L CO₂

x=2.5 L
4 0
3 years ago
Matter in the ____state completely fills the volume of its container
balu736 [363]

Answer:

Gas state

Explanation:

Gas particles spread out to fill a container evenly, unlike solids and liquids.

5 0
3 years ago
Read 2 more answers
Group 8A of the periodic table contains the A. most reactive nonmetals. B. least reactive nonmetals. C. most reactive metals. D.
aivan3 [116]

Answer: The correct answer is option B.

Explanation: There are 7 elements in group VIII-A. They are Helium (He), Neon(Ne), Argon(Ar), Krypton (Kr), Xenon (Xe), Radon (Rn) and Ununoctium (Uuo). They are considered as a part of group 18.

Metals are shown in purple color in the periodic table. Metalloids as blue color and Non-metals are shown in green color.

Group VIII-A elements have fully filled orbitals and hence are most stable amongst all the elements in the periodic table. They are considered as least reactive elements and as they are categorized as non-metals. So, they are the least reactive non-metals.

Therefore, the correct option is B.

7 0
3 years ago
Read 2 more answers
Calculate the amount of HCN that gives the lethal dose in a small laboratory room measuring 12.0 ft×15.0 ft×8.60ft.
garik1379 [7]

<u>Given:</u>

Dimensions of the room= 12 ft * 15 ft * 8.60 ft

<u>To determine:</u>

The amount of HCN that gives the lethal dose in the room with the given dimensions

<u>Explanation:</u>

As per the World Health Organization, the lethal dose of HCN is around 300 ppm

300 ppm = 300 mg of HCN/ kg of inhaled air

Volume of air = volume of room = 12 * 15 *8.6 = 1548 ft³

Now,  1 ft³ = 28316.8 cm³

Therefore, the calculated volume of air corresponds to:

1548 * 28316.8 = 4.383 * 10⁷ cm3

Density of air (at room temperature 25 C) = 0.00118 g/cm3

Thus mass of air corresponding to the calculated volume is

Mass = Density * volume = 0.00118 g/cm3 * 4.383 * 10⁷ cm3

= 5.172*10⁴ g = 51.72 kg

Lethal amount of HCN corresponding to 51.72 kg of air would be.

= 51.72 kg air* 300 mg of HCN/1 kg air = 15516 mg

Ans: Lethal dose of HCN = 15.5 g

7 0
3 years ago
What is oxidation number​
MariettaO [177]

Antimony also forms trihalides and pentahalides, such as SbF3 , where its oxidation state is +3, and SbF5 , where its oxidation state is +5

7 0
3 years ago
Other questions:
  • Determine the number of atoms of O in 92.3 moles of Cr3(PO4)2
    7·1 answer
  • Aqueous solutions of copper (II) bromide and silver (1) acetate react to form solid
    5·1 answer
  • An element with 7 valence electrons will most likely
    6·1 answer
  • Elements named after mythological beings
    7·1 answer
  • How many Liters of I2 are produced when 241.6 grams of KI are reacted with excess CuBr2?
    11·1 answer
  • Plants are living organisms that respond to stimuli, use resources for energy, grow and develop, are organized by cells, and rep
    9·2 answers
  • An ideal gas resides in a closed cylinder (diameter is 0.5 ft) with a frictionless piston. The initial conditions are 139 mol of
    7·1 answer
  • If we react 30 grams of ethane (C2H6 ) with 320 grams of oxygen, how many grams of carbon dioxide would we make
    6·1 answer
  • In what type of climate do trees produce narrower rings?
    13·1 answer
  • Calculate the pH during the titration of 40.00 mL of 0.1000 M HCl after adding 50 mL of 0.1000 M NaOH:
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!