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
WITCHER [35]
3 years ago
11

Due to food scarcity in ancient times people had to spend

Chemistry
1 answer:
Umnica [9.8K]3 years ago
6 0
The answer is A as they had to spend time growing or looking for food as food was scarce back then.
You might be interested in
What is the advantage of having valves in the
fenix001 [56]
The valves stop the blood from flowing backwards
6 0
3 years ago
In a certain industrial process involving a heterogeneous catalyst, the volume of the catalyst (in the shape of a sphere) is 10.
olga nikolaevna [1]

Answer:

a. The second run will be faster.

d. The second run has twice the surface area.

Explanation:

The rate of a reaction is proportional to the surface area of a catalyst. Given the volume (V) of a sphere, we can find its surface area (A) using the following expression.

A=\pi ^{1/3} (6V)^{2/3}

The area of the 10.0 cm³-sphere is:

A=\pi ^{1/3} (6.10.0)^{2/3}=22.4cm^{2}

The area of each 1.25 cm³-sphere is:

A=\pi ^{1/3} (6. 1.25)^{2/3}=5.61cm^{2}

The total area of the 8 1.25cm³-spheres is 8 × 5.61 cm² = 44.9 cm²

The ratio of  8 1.25cm³-sphere to 10.0 cm³-sphere is 44.9 cm²/22.4 cm² = 2.00

Since the surface area is doubled, the second run will be faster.

6 0
3 years ago
Mercury has an atomic mass of 200.59 amu. calculate the mass of 3.0 x 10^10 atoms
Licemer1 [7]
To determine mass of the given number of atoms of mercury, we need a factor that would relate the number of atoms to number of moles. In this case, we use the Avogadro's number. It is a <span>number that represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. The number of units could be atoms, molecules, ions or electrons. To convert into mass, we use the given amu of mercury since it is equal to grams per mole. We calculate as follows:

</span>3.0 x 10^10 atoms ( 1 mol / 6.022 x 10^23 atoms ) ( 200.59 g / 1 mol ) = 9.99x10^-12 g Hg
5 0
3 years ago
What's the equation for the reaction of Trifluoro bromide with Ammonia gas. ( brainliest assured )​
sp2606 [1]

Answer:

Ammonium bromide can be prepared by the direct action of hydrogen bromide on ammonia. It can also be prepared by the reaction of ammonia with iron(II) bromide or iron(III) bromide, which may be obtained by passing aqueous bromine solution over iron filings.

Explanation:

please mark me as brainliest thank you

5 0
3 years ago
Air is made of mostly oxygen, nitrogen, argon, carbon dioxide, and small amounts of other substances. Air is a ___________.
mixas84 [53]
 <span>Air is a homogeneous mixture.</span>
5 0
3 years ago
Read 2 more answers
Other questions:
  • What is the molarity of a solution that contains 4.13g of magnesium bromide in 0.845 L of solution
    9·1 answer
  • What does the law of conservation of energy state?
    9·1 answer
  • Which of the following indicates 4 molecules of water?​
    11·2 answers
  •  Based on the size and shape of the clasts in the sedimentary rock shown in the image, which classification would geologists mos
    13·2 answers
  • Express your answer as a chemical equation. Identify all of the phases in your answer. Enter noreaction if no precipitate is for
    5·1 answer
  • What is the mass number of a carbon atom which has 7 neutrons?
    5·1 answer
  • What is a controlled variable, a manipulated variable, and a responding variable in a science experiment??
    8·1 answer
  • What source of thermal energy does an internal combustion engine use?
    13·2 answers
  • Describe the neutral signaling pathway
    14·1 answer
  • What mass of carbon monoxide is needed to react with 1000g of iron oxide?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!