Answer:
4
Explanation:
According to the question, one box of jello has a mass of 250grams.
The question wants us to find how many boxes of jello would collectively weigh 1kg.
Since the units of weight here are in grams (g) and kilograms (kg), we need to convert to the same unit
1kilogram (kg) is equal to 100 grams (g).
Hence, if 1 box of jello weighs 250g
1000g of jello box will be 1000/250 in number
1000 ÷ 250 = 4.
Hence, 4 boxes of jello will weigh 1000g or 1kg.
Answer: C. 0.4
64% of the population have dominant phenotype which means they’re either BB or Bb. The other 36% of the population have bb genotype. If this population is in equilibrium then f(b)=rad0.36=0.6 and as u know f(b)+f(B)=1. So 1-0.6=0.4.
Hope this helps:))
Answer:
1) A chemical reaction is shown.
SnO2 + H2 → Sn + H2O
What is true about this chemical reaction?
B.
It is unbalanced because the mass of the reactants (number of atoms) is greater than the mass of the products (number of atoms).
2) Read the information about an experiment.
Jadon plans on carrying out an experiment involving the burning of steel wool to illustrate the conservation of mass. Steel wool is made of iron. When it is burned it combines with oxygen to form iron(III) oxide.
Which step in his experiment is the most important if he wants his experiment to correctly demonstrate the conservation of mass?
A.
The steel wool should be burned inside of a sealed jar or other closed system.
Explanation:
The explanation to number 1 is that I selected it in my test and got it.
The explanation the number 2 is from the link below:
https://quizizz.com/admin/quiz/5dee60258f1145001bc02ed5/physical-science-2nd-9-weeks-practice-test-2020
Answer: The greenhouse gas emissions from the extraction of bitumen and the use of large quantities of water.
Explanation:
Bitumen is a natural flammable organic matter formed from kerogen in the process of petroleum generation, which is soluble in carbon disulfide. Asphalt and mineral wax are examples of hydrocarbons which are part of bitumen. Conventional oil is extracted by wells while <u>oil sands deposits are extracted using surface mining sectioning techniques, or are flowed to wells by in situ techniques that reduce bitumen viscosity by steam and/or solvents.</u> So, unlike crude oil extracted in oil wells, bitumen requires an open-pit mining operation, in which large tracts are washed with a mixture of water and chemicals to separate the bitumen from a mixture of sand and clay.
Two consequences of this practice are:
- The greenhouse gas emissions from the extraction of bitumen are larger than the extraction of conventional oil. The emissions produced contribute to enhance the greenhouse effect and cause global warming. The greenhouse effect occurs when certain gases retain part of the energy emitted by the earth's soil when heated by the sun's radiation. This phenomenon occurs naturally, and thanks to it, the average temperature of the Earth is about 14º C (57.2 °F). The problem occurs when these greenhouse gases increase in the atmosphere and the amount of energy that is not released into space also increases and, with it, the Earth's temperature.
- The extraction of bitumen from oil sands requires the use of large quantities of water, and even though water used here can be recycled, only a small amounts is returned to the natural cycle. Also, spills from the transportation of the oil could damage soils and waterways, increasing water pollution. This toxic water could get into surface.
Answer:
lungs. that is why it is called respiratory system
Explanation:
