"Changing water salinity" is the most significant challenge for organisms that live in estuaries.
<u>Answer:</u> Option D
<u>Explanation:</u>
For estuaries, alkalinity levels are usually the maximum at a river's mouth where the ocean water falls for, and the minimum upstream where freshwater falls in. Although salinity vary throughout the tidal cycle. In estuaries, salinity rates usually decrease in spring as snow melt and rain raises the freshwater flow from streams and groundwater.
It influences the chemical environments within the estuary, especially the dissolved oxygen (DO) levels in the water. The level of oxygen that would get dissolved in water or its solubility get declined when the alkalinity rises.
The direction of an electric field is determined from the behavior of a positive test charge that is set free in the electric field.This charge moves along a distinct vector showing the direction of the electric field Therefore the answer is b. a positive charge will move in the field.
Answer:
Incomplete question: The masses of the blocks m₂ = 1.5 kg and m₃ = 2 kg
Explanation:
Given data:
L₁ = length = 0.85 m
L₂ = 0.25 m
L₃ = 0.5 m
m₂ = 1.5 kg
m₃ = 2 kg
Question: Find the unknown mass of the block 1 needed to balance the bar, m₁ = ?
The torque is zero (intermediate point of the bar)

Is negative because mass 1 is to the left of the coordinate system (see the diagram)

Answer:
Temperature affects phase change by slowing down the movement in between the atoms, thus causing a change in kinetic energy, which in turn causes the atoms to undergo forms of combining or a type of disepersion.
Explanation:
Kinetic energy while being the reason phase changes are constant, Kinetic Energy can be caused by other means. Pressure and temperature can affect many other states kinetic energy, which in turn can affect each state of matter. Making a group of atoms or compounds compacts will force the atoms to move closer together thus with a lower net kinetic energy energy. Reducing temperature also works along the same lines. Colder temperatures can slow down atomic movements which in turn will naturally make each atom move close to each other.
With all of the information provided, it is only feasible that pressure and temperature are directly corresponding with the matter and atomic phase change
Answer:a) Water is relatively resistant to an increase in temperature
Explanation:
Water has relatively high heat capacity i.e. it requires high amount of heat to raise a little increase in temperature.
Heat capacity is defined as ability of molecule to absorb heat . Mathematically heat capacity is defined as

where 
