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
eimsori [14]
3 years ago
10

What are the horizontal rows on the periodic table numbered 1-7 called?

Chemistry
2 answers:
gregori [183]3 years ago
7 0

periods of the periodic table

NeTakaya3 years ago
3 0

Answer: They're called Periods

You might be interested in
How does the addition of salt to solid ice affect the melting transition from solid to liquid?
serious [3.7K]

Answer:

Im sure the answer is c

Hope this helped have a good day :) please mark me the brainliest answer?

7 0
3 years ago
Read 2 more answers
A sample contains 25% parent isotope and 75% daughter isotopes. If the half-life of the parent isotope is 72 years, how old is t
alisha [4.7K]

The radioactive decay obeys first order kinetics

the rate law expression for radioactive decay is

ln\frac{[A_{0}]}{[A_{t}]}=kt

Where

A0 = initial concentration

At = concentration after time "t"

t = time

k = rate constant

For first order reaction the relation between rate constant and half life is:

k=\frac{0.693}{t_{\frac{1}{2} } }

Let us calculate k

k = 0.693 / 72 = 0.009625 years⁻¹

Given

At = 0.25 A0

ln(\frac{A0}{0.25A0})=0.009625  X time

time = 144 years

So after 144 years the sample contains 25% parent isotope and 75% daughter isotopes**

Simply two half lives

5 0
3 years ago
Read 2 more answers
if 2.0 g of hydrogen sulfide, H2S(g) reacts with 5.0 g of sodium hydroxide what mass of the excess reactant is present when the
Ronch [10]

Answer: iits 9.g

Explanation:

7 0
3 years ago
If the same materials are used to build a voltaic cell and an electrolytic cell, how would the chemical reactions compare?
nadya68 [22]
In the electrolytic cell, depending on the polarity of the battery, either a more vigorous reaction (though the same as the voltaic cell) would occur, or the reverse would.
3 0
4 years ago
Why was mass lost from the crucible during the reaction?
Alexxandr [17]
If the crucible wasn't covered with a lid the reactants may have produced a gas that was released into the surroundings, or mass may have been lost in the form of water vapour.
6 0
3 years ago
Other questions:
  • Please help me thank you :)
    10·2 answers
  • Carbon reacts with oxygen to produce carbon dioxide (CO2 (g), Delta.Hf = –393.5 kJ/mol) according to the equation below. Upper C
    8·2 answers
  • How many valance Elton’s does aluminum have
    11·2 answers
  • Is hot chocolate a pure substance or a mixture? Explain.
    15·1 answer
  • Genetic engineers must modify eukaryotic genes so that they can be expressed in bacterial host cells. The DNA from a eukaryotic
    9·1 answer
  • Is the following statement sometimes, always or never true: Compounds
    15·1 answer
  • What is the correct name for Mg3S2
    10·1 answer
  • Which of the following substances feels slippery and will not react with metals? *
    13·1 answer
  • Based on Table F, which compound is least soluble in water?
    10·1 answer
  • Cu2O + C-&gt;<br> Cu + CO2<br> Balance the above reaction by writing in the correct coefficient.
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!