CHo các nguyên tử X, Y, Z thỏa mãn những điều kiện sau: Nguyên tử X có khối lượng =40, hạt nhân có chứa 22 hạt proton
Nguyên tử X có 3 lớp e, lớp ngoài cùng có 7 electron
Phân mức năng lượng cáo nhất trong nguyên tử Z là 4s1
a) viết cấu hình e của X, Y, Z. Cho biết nguyên tố nào là kim loại, phi kim hay khí hiếm
b) xác định vị trí của X, Y, Z trong bảng tuần hoàn
c) viết công thức ô-xit cao nhất, hidroxit tương ứng, hợp chất khí với hidro

Note that 2 mol dm⁻³ = 2 mol/(dm³)outline: we're given the concentration of hcl, which is  2 mol dm⁻³ (cubic meters in the denominator can represent volume, so i know this is concentration). we're an amount of calcium carbonate caco₃, which is 5 g. we're presented with a chemical equation which includes caco₃ and hcl. we are told to find the volume of hcl. from what we see so far, this seems to be a stoichiometry  problem. we'll have to use the given information about calcium carbonate to find the amount of moles of hcl needed to fully react with calcium carbonate. then we'll have information about the moles of hcl and the concentration of hcl; that will be enough to figure out volume according to the formula concentration = moles / volume.======all the answer choices are not in dm.convert the given concentration so that it uses cm⁻³.we can use conversion factors. we have to cube our conversion factors so that dimensional analysis works.we can convert to meters first, using the fact that     10 dm = 1 m  ⇔ 10³ dm³ = 1 m³then we use the fact that     10² cm = 1 m ⇔ (10² cm)³ = (1 m)³ ⇔ 10⁶ cm³ = 1 m³so converting:     now we have to find the moles of hydrochloric  acid neededfind the moles of calcium carbonate. we have to find the molar mass of calcium carbonate, caco₃, which can be found by    molar mass = (mass ca) + (mass c) + 3(mass o)    = 40 + 12 + 3(16)    = 100 g/molconvert the given 5 g to moles:     mol caco₃ = 5 g caco₃ * 1 mol/(100 g) = 0.05 mol caco₃use stoichiometry (ratios) to figure out the moles of hcl needed. ratio wise, there's 2 hcls for every caco₃, so use dimensional analysis    mol hcl = mol caco₃ * (2 mol hcl) / (1 mol caco₃)    = 0.05 mol hcl * 2    = 0.1 mol hcl  we have 0.1 mol hcl and concentration of hcl (0.002 mol/cm³).we need to find volumesince concentration = moles / volume, rearrange to get     volume = moles / concentration    volume = 0.1 mol / (0.002 mol/cm³)    volume = 50 cm³

Change of state has wrong energy change - option 2

brian made this table to organize his notes on changes of state. depostion is a change of state that has the wrong energy change listed. it is utilized to collect data as a portion of the development means and in restricted conditions which may be applied at test.

a deposition in the authority of the united states or research for development in the authority of canada includes the catching of affirmed. the out-of-court verbal assertion of a spectator that may be lessened to a printed record for succeeding application for discovery purposes.

Ibelieve it’s 1.95m