Answer:
Option A) Na
Explanation:
From the options given above, sodium (Na) is most likely to lose electron to form ion
Na is a group 1 metal. Metals form ions by losing electron(s).
From the options given above, only Na is a metal and so it is most likely to form ion by losing electron
Physical properties help identifying a substance and how it changes.
For example: if a substance crushes easily that means it has a low density, but if it’s hard and doesn’t crush easily, that means it has a strong high density.
And eventually the substance would not end up forming a new substance.
Look at the picture below to understand more about physical changes.
Answer:
A. -163.96kJ
B. -158.34kJ
Explanation:
Heat of combustion is the heat released when an element with oxygen at stp.
Reaction for the combustion of carbon:
C(s) + O2(g) --> CO2(g)
Enthalpy heat of combustion, C (using Hess law) = -393.5 kJ/mol
m = 5g
Molecular weight = 12 g/mol
No of moles = mass/molecular weight
= 5/12
= 0.417mol
DH = -393.5 * 0.417
= -163.96 kJ
B. Heat absorbed by the calorimeter = heat evolve by combustion
= mCH2ODT + mCcDT
Where CH2O is the specific heat capacity of the water in the calorimeter
Cc is the specific heat capacity of copper calorimeter
= (2500*4.184*14.1) + (2000*0.385*14.1)
= -158343J
= -158.34kJ
1]Well if the planets were removed the pray would have no food to eat, because of this the food chain would most likely die out, or the pray would need to find a new location with materials they can consume.
2]Explain how energy is transferred through food chains and food webs in an ecosystem. Energy is transferred through the separate trophic levels of a food chain or web by feeding.The first trophic level (producers) is that of plants which are examples of autotrophs – they make their own food.
Answer:
2.94 x 10⁻¹⁴L
Explanation:
To solve this problem, we have to assume that the condition of this water is at standard temperature and pressure, STP.
At STP;
1 mole of gas have a volume of 22.4L
So, let us find the number of moles of this water first;
6.02 x 10²³ molecules can be found in 1 mole of a substance
7.89 x 10⁸ molecules will contain
= 1.31 x 10⁻¹⁵mole of water
So;
Volume of water = 22.4 x 1.31 x 10⁻¹⁵ = 2.94 x 10⁻¹⁴L