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Fudgin [204]
3 years ago
12

What is the mass number of an atom which contains 21 electrons, 21 protons, and 24 neutrons?

Chemistry
1 answer:
murzikaleks [220]3 years ago
7 0
45 is the atomic mass of the atom. And the name is Scandium 
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If a 50 kg student is pushed in a rolling chair with a force of 20 N, what is the student’s acceleration?
Leokris [45]

Answer:

0.4m/s²

Explanation:

Given parameters:

Mass of student = 50kg

Force  = 20N

Unknown:

Acceleration = ?

Solution:

From Newton's second law of motion,

          Force  = mass x acceleration

   Acceleration  = \frac{Force }{mass}   = \frac{20}{50}    = 0.4m/s²

8 0
3 years ago
Which represents the overall (net) reaction of this mechanism: step 1: H2O2 + I- → H2O + OI- step 2: H2O2 + OI- → H2O + O2 + I-
11111nata11111 [884]

Answer:

A. 2H₂O₂  → 2H₂O + O₂

Explanation:

  • 1. H₂O₂ + I⁻ → H₂O + OI⁻
  • 2. H₂O₂ + OI⁻ → H₂O + O₂ + I⁻

If we <u>make a net sum of both reactions</u>, we're left with:

  • H₂O₂ + I⁻ + H₂O₂ + OI⁻ → H₂O + OI⁻ + H₂O + O₂ + I⁻

Grouping species:

  • 2H₂O₂ + OI⁻ + I⁻ → 2H₂O + OI⁻ + O₂ + I⁻

There is OI⁻ at both sides, so it is eliminated -same goes for the catalyst, I⁻-.

  • 2H₂O₂  → 2H₂O + O₂

Thus the answer is option A.

4 0
3 years ago
The stability of an isotope is based on its
sattari [20]
Option 4. ratio of electrons to protons

Isotope that has atomic number of 82 is stable. An element that has an atomic number ∠82 more stable except Tc and Pm. Also there is the concept that isotopes consisting a combination of even-even,even-odd,odd-even, and odd-odd are all stable. Many isotopes with no magic numbers of nucleons are stable
7 0
2 years ago
SOS TESTING:
andrezito [222]

Answer:

Condensation

Explanation:

An exothermic process is one in which heat is lost. Condensation is a change of state from gas to liquid. Thus is loses heat.

HOPE THIS HELPED

4 0
3 years ago
If gas is $4.00/gal, how much does it cost to travel from Portland, Maine, to Orlando, Florida (a distance of 1,500 mi)? Give yo
AlexFokin [52]

it cost $200 , the answer is not $6000

6 0
3 years ago
Read 2 more answers
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