Technically, the answer is iron. Oxygen has a melting point way below zero (-219 degrees celsius), ice becomes water AT room temperature and bromine is already a liquid at room temperature. So, iron has a melting point greater than room temperature due to the fact that metals are made up of giant structures of atoms in a regular arrangement, and there are strong forces of electrostatic attraction between positive metal ions and negative electrons, meaning that a lot of heat energy is required to break the bonds, i.e. a very high melting point, approx. 1500 degrees celsius. Hope this helps.
D should be the correct answer. isotopes are atoms that have the same atomic number (number of protons) but different atomic masses (number of protons and neutrons). isotopes also have the same number of electrons since atoms need to have equal numbers of protons and electrons to not be considered ions. Since the number of protons determines the chemical properties of the atom, we can say that all isotopes have the same chemical properties due to the fact that all isotopes have the same atomic number.
I hope this helps. Let me know in the comments if anything is unclear.
Balanced equation:
Ca(OH)2+H2SO4=CaSO4+2 H20<span />
Answer:
38.3958 °C
Explanation:
As,
1 gram of carbohydrates on burning gives 4 kilocalories of energy
1 gram of protein on burning gives 4 kilocalories of energy
1 gram of fat on burning gives 9 kilocalories of energy
Thus,
27 g of fat on burning gives 9*27 = 243 kilocalories of energy
20 g of protein on burning gives 4*20 = 80 kilocalories of energy
48 gram of carbohydrates on burning gives 4*48 = 192 kilocalories of energy
Total energy = 515 kilocalories
Using,
Given: Volume of water = 23 L = 23×10⁻³ m³
Density of water= 1000 kg/m³
So, mass of the water:
Mass of water = 23 kg
Initial temperature = 16°C
Specific heat of water = 0.9998 kcal/kg°C
Solving for final temperature as:
<u>Final temperature = 38.3958 °C </u>
The formula for average atomic mass is :
mass of isotope A * % of isotope A + mass of isotope B * % of isotope B + ....
Now,
Here,
Average atomic mass of nitrogen = (14.003 * 99.63%) + (15.000 * 0.37%)
= (14.003 * 0.9963) + ( 15.000 * 0.0037)
= 13.951 + 0.056
= 14.007 a.m.u.
