Answer:
1 × 10²⁴ atoms O
General Formulas and Concepts:
<u>Chemistry - Atomic Structure</u>
- Reading a Periodic Table
- Using Dimensional Analysis
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
Explanation:
<u>Step 1: Define</u>
30 g O
<u>Step 2: Identify Conversions</u>
Avogadro's Number
Molar Mass of O - 16.00 g/mol
<u>Step 3: Convert</u>
<u />
= 1.12913 × 10²⁴ atoms O
<u>Step 4: Check</u>
<em>We are given 1 sig fig. Follow sig fig rules and round.</em>
1.12913 × 10²⁴ atoms O ≈ 1 × 10²⁴ atoms O
Answer:
1/32 of the original sample
Explanation:
We have to use the formula
N/No = (1/2)^t/t1/2
N= amount of radioactive sample left after n number of half lives
No= original amount of radioactive sample present
t= time taken for the amount of radioactive samples to reduce to N
t1/2= half-life of the radioactive sample
We have been told that t= five half lives. This implies that t= 5(t1/2)
N/No = (1/2)^5(t1/2)/t1/2
Note that the ratio of radioactive samples left after time (t) is given by N/No. Hence;
N/No= (1/2)^5
N/No = 1/32
Hence the fraction left is 1/32 of the original sample.
Answer: To find the charge of an ion you must add the charge of protons and charge of electrons of an element.
Explanation: By doing this you get the overall charge of the ion.
Answer:
The answer to your question is the second choice
Explanation:
Formula to calculate the heat of any substance
Q cal= mCcal ΔTcal
Formula to calculate the heat of a metal. The heat will be negative because it releases heat.
Qm = -mCmΔTm
Now equal both formula
Qcal = Q m
mCcalΔTm = -mCmetΔTmet
-Solve for Cmet
Cmet = -[mCcalΔTm] / mΔTmet
