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3 years ago

Question 1

1 answer:

4 0

Question 1Which of the following describes the treatment in an investigation?

the factor that is changed in order to observe a response

Question 2
Which statement best describes an independent variable?

The variable you change in an investigation

Question 3
Liam did an investigation to see how water temperature affects the amount of salt that will dissolve in the water. He filled 4 beakers with exactly 100 milliliters of water each. He then heated each beaker to a different temperature and tested salt solubility at each different temperature. What was Liam's independent variable?

the temperature of the water in each beaker

Question 4
Which of the following is an example of a treatment?

Changes made to the temperature of a greenhouse

Question 5
Jose is curious about which home remedy removes skunk smell from his dog. Which of the following is a variable that must be kept constant?

The home remedy used

Question 6
It is not important to make sure that all variables other than the independent variable are kept constant.

False

Question 7
In order to determine whether or not a substance is an acid or a base, you may stick your finger in the container and make your decision based on whether or not your finger feels slippery.
False

Question 8
A poison hazard symbol means your should not let chemicals contact your skin, ingest or inhale the substance.

True

Question 9
Repeating an experiment is important because

it reduces the chance of error

Question 10
When using repeated trials during a scientific investigation, scientists should find the average of their data for use in their final report.

True

You might be interested in

In which of the following equilibrium systems will an increase in the volume cause the equilibrium to shift away from the reacta

Alenkinab [10]

Answer: 2NOBr(g) ⇌ 2NO(g) + Br2(g)

Explanation: For volume changes in equillibrium, the following are to be taken into consideration:

Volume changes have no effect on equillibrium system that contains solid or aqueous solutions.
An increase in volume of an equilibrium system will shift to favor the direction that produces more moles of gas.
A decrease in volume of an equilibrium system will shift to favor the direction that produces less moles of gas.
Volume changes will have no effect on the equillibrium system if there is an equal number of moles on both sides of the reaction.

2NOBr(g) ⇌ 2NO(g) + Br2(g) is the equillibrium system because there are more moles of products,therefore an increase in the volume of the reaction will shift to the right and produce more moles of products. Also both reactants and products exist in the gaseous state and does not have equal number of moles.

5 0

3 years ago

In the PhET simulation window, click the radio button labeled Mystery in the Blocks menu on the right-hand side of the screen. U

Yuliya22 [10]

Answer:

B, D, E, C, A

Explanation:

We have 5 blocks with their respective masses and volumes.

Block Mass Volume

A 65.14 kg 103.38 L

B 0.64 kg 100.64 L

C 4.08 kg 104.08 L

D 3.10 kg 103.10 L

E 3.53 kg 101.00 L

The density (ρ) is an intensive property resulting from dividing the mass (m) by the volume (V), that is, ρ = m / V

ρA = 65.14 kg / 103.38 L = 0.6301 kg/L

ρB = 0.64 kg / 100.64 L = 0.0064 kg/L

ρC = 4.08 kg / 104.08 L = 0.0392 kg/L

ρD = 3.10 kg / 103.10 L = 0.0301 kg/L

ρE = 3.53 kg / 101.00 L = 0.0350 kg/L

The order from least dense to most dense is B, D, E, C, A

4 0

2 years ago

The atomic mass of Cu is 63.5. Find its electrochemical equivalent

FrozenT [24]

Answer:

The electrochemical equivalent of copper, Cu, is 3.29015544 × 10⁻⁷ g/C

Explanation:

The given parameters are;

The element for which the electrochemical equivalent is sought = Copper

The atomic mass of copper = 63.5

The electrochemical equivalent, 'Z', of an element or a substance is the mass, 'm', of the element or substance deposited by one coulomb of electricity, which is equivalent to a 1 ampere current flowing for a period of 1 second

Mathematically, we have;

m = Z·I·t = Z·Q

We have;

Cu²⁺ (aq) + 2·e⁻ → Cu

Therefore, one mole of Cu, is deposited by 2 moles of electrons

The charge carried one mole of electrons = 1 Faraday = 96500 C

∴ The charge carried two moles of electrons, Q = 2 × 96500 C = 193,000 C

Given that the mass of an atom of Cu = 63.5 a.m.u., the mass of one mole of Cu, m = 63.5 g

$Z = \dfrac{m}{Q} = \dfrac{63.5 \ g}{193,000 \ C} = 3.29015544 \times 10^{-4} \, g \cdot C^{-1}$

∴ Z = 3.29015544 × 10⁻⁴ g/C = 3.29015544 × 10⁻⁷ g/C

The electrochemical equivalent of copper, Cu, is Z = 3.29015544 × 10⁻⁷ g/C

7 0

3 years ago

Something that can be broken down by living organisms is

Aloiza [94]

The answer is A: biodegradable.

5 0

2 years ago

the polio virus is 25 nanometers in diameter. How many would fit across the head of a pin 2 millimeters in diameter

IrinaVladis [17]

2mm=2,000,000 nm
2,000,000/25=80,000
The answer is 80,000 polio viruses

6 0

3 years ago

Read 2 more answers